Updates on what Oslo is and Quadrant not is (September 2009)

It has been more quiet around “Oslo” the last month. Maybe just about everybody is on vacations. Or people feel that everything will change with the PDC in November and are afraid of publishing nonsense.

Nonetheless, I felt it’s time for an update on what I think, heard and read about “Oslo”.

I divided my post in two sections:

  • Information about “Oslo”
  • What I think about “Oslo” today

have fun!

Some Information about “Oslo”

For those who don’t know, “Oslo” is the current codename for Microsoft’s forthcoming modeling platform, which is available as CTP Download since back in October 2008.

If you want to read more about what Oslo is about, I recommend those Resources:

Well, since then Microsoft has released two more CTP releases (January and May), written a lot of documentation and posted quite some videos and samples. If you ask me, it’s yet too much for such a young and undone technology. Oslo’s modeling language “M” has and The "Oslo" Modeling Language Specification, which yet has been implemented in JavaScript by Mathew Wilson (jsmeta).

The community did also care a lot, and there are even companies investing in tools around “Oslo”. Telrik published two projects on their Labs Site. A tool for comparing and migrating M as well as LINQ to M. There are even trainings offered by Agilitrain and PluralSight.

Some recommended links:

What I think about Oslo today
(May CTP + Announcements)

First of all I want to say, that I’m happy Microsoft released Oslo in such an early state. I think they know the pros and cons of such an open process. The community can help with forming the product, and companies can start to invest early in what they think might be valuable for the future. But It also means more friction for any changes that are made.

I have used M for defining schemas and languages and also played around with the Repository and Quadrant. As Microsoft also states, it’s early Alpha. I stumbled over many bugs which I still plan to report and blog about. But that is OK, no one ever said it was production ready.


So far I like the schema part of M, also called MSchema. It has a very concise (compared to XSD) c-style syntax and covers a lot of what I want to express when modeling information structures. The M-graph (for values) syntax is also OK, while I don’t like the MGraph API. M-constraints let you restrict your types in a nice way. What I don’t like here, is the missing support for weak constraints. Named M-queries (similar to LINQ syntax), are a nice way to query M structures.

M-grammar is useful for DSLs. I think it could be more opinionated. I feel MS is striving for an expressiveness that let you describe all computer languages in the world using MGrammar. This makes it more complex than necessary for covering DSLs. At the same time it doesn’t support nesting of languages, which would be especially useful for DSLs, because you often need to talk to external models (e.g. pinvoke). The support for editor customizing (crucial language workbench feature) as it is today is not sufficient and too hard to configure.

Another feature I miss here is referencing between nodes and even across files (linking + scoping). For now all references are just values (ids), and the output of a DSL program will be a tree model, no graphs!

The Repository

The Repository basically offers some features on-top of SQL server as are row-level security, hierarchies, localization, versioning, additional constraints. All those features are plain SQL “libraries” in conjunction with M-models which also are compiled down to SQL. I don’t yet know what to think about the Repository.

Naming / Packaging

In the last couple of weeks the Oslo team published two posts that confirmed some of my speculations.

Let’s start with Doug’s Post: On “Oslo” at Douglas Purdy

In this post he basically makes two statements:

The only thing that I feel bad about is that we kept the “Oslo” name around so long (you will see that change at the next PDC), which has continued to be a confusing point for customers (“I thought Oslo was your new SOA platform”).

Douglas Purdy

I agree. It was confusing. Although people slowly start to accept “Oslo” as for “Modeling”.

Oslo and EF / Data Programmability

With this in mind, we made a decision to merge the Data Programmability team (EDM, EF, Astoria, XML, ADO.NET, and tools/designers) and the “Oslo” team (“Quadrant”, Repository, “M”) together.

Douglas Purdy

I don’t yet know what to think about this. “Oslo” is not and should not evolve to an O/R-Mapper. M’s type system is structural and doesn’t map well to strongly typed objects as used by EF. I can see this choice limiting the modeling capabilities of Oslo. But I guess we have to wait and see.

Quadrant. A graphical Editor?

The other post, confirming my fears about Quadrant was Model Citizen : What’s So Compelling about "Quadrant" Anyway?.

Back in November last year, when I wrote a sum-up post about “Oslo” I concluded Quadrant:

Yes. Quadrant lets you interact with models graphically. It’s highly generic, customizable and it looks great.

Lars Corneliussen, November 2008, What "Oslo" is and is not

I concluded this from the official statement about Oslo plus some videos and screenshots I had seen.

A tool that helps people define and interact with models in a rich and visual manner

Doulas Purdy, September 2008, What is Oslo?

But here is the smackdown:

Microsoft code name "Quadrant" is a ‘tool for viewing and editing SQL data,’ but… so what?

Michael Murray, July 2009, What’s So Compelling about "Quadrant" Anyway?

As I understand today, and as it shows up in the May CTP, it is not a graphical editor or graphical editing toolkit but rather a light WPF-version of Microsoft Office Access that understands Oslo Modeling concepts and relationships and builds up default editors in a generic manner. This is still useful (if it is free), but not far as useful as what I hoped Quadrant to be.

Please, Microsoft, make Quadrant a graphical editing toolkit with good support for configurable diagramming and any custom WPF editors. It should also have the plug-in model VS2010 offers for sharing any extensions.

The “Oslo” Story

Microsoft tries to sell “Oslo” as if it was all one story. It’s a lie.

There is tons of impedance mismatches that restrict you in many ways.

Modeling Structure

  • M in general uses structural typing (duck typing, supports mix-ins) and supports real graphs (including references)
  • MGrammar ASTs are hierarchal (tree structure) and for now only supporting nodes and strings.
  • Databases store flat relational data,
  • and objects in the .NET world are typed nominally (no multiple inheritance).

DSLs + Repository

There is no story for “DSLs and the repository”, and there is not yet a good story for any runtime support off the repository or DSL files. It’s basically what you had before. You can either access the database via ADO.NET or an O/R-Mapper or you run directly off the parsed MGraph-AST representing your DSL-Script, which feels like visiting xml documents. M has a nice LINQ-ish query language, but that doesn’t work in memory against a graph.


M has good support for complex data structures. As said there is no support for in-memory queries. But even the database implementation is limited by it’s relational backend. Even though queries can consult complex properties for sorting or filtering, it can only return rows with a list of scalar fields.


Most constraints on types are only implemented in the SQL-Mapping. Also here there is no in-memory implementation that would validate your model against a schema. Basically the M-compiler generates a database schema including checks that would not let you insert invalid data into the database.

Data and schema evolution

There is this dream about capturing requirements in quite fuzzy ways and then piece for piece add details to them – until they have reached some formal state that might be executable. This sounds nice in theory, but there is no chance to implement this stuff. M is very easy to change, and it is easy to add constraints and refactor schema structures. But there is no story around how to let your data evolve together with your schemas using the Repository. So, besides nice theories, Oslo doesn’t help here.

More to come

There will be new content and Chris Sells also announced a fresh CTP around this years PDC in November.

So far, only one session has been scheduled, but watch this list for more sessions to come: Microsoft PDC09 – Modeling Sessions

Hope to see you in LA in November!


dotnetpro 07/2009 – Turmbau zu Babel – DSLs entwickeln mit Eclipse Xtext

Der zweite Artikel unserer DSL-Serie bei der dotnetpro ist raus. Warum der Artikel Turmbau zu Babel heißt weiß ich nicht 🙂

Bild 2

Abstract: Domänenspezifische Sprachen sind eines der vielen Mittel, um Software zu industrialisieren und vor allem zu automatisieren. Praxisnah zeigt dieser Artikel eine DSL für den Import von Mainframe-Exporten – zum Beispiel, um Daten von einem Mainframe zu importieren und dabei zu konvertieren. Eclipse Xtext leistet beim Erstellen einer passenden DSL hervorragende Dienste.

Autoren: Markus Völter und Lars Corneliussen

Microsoft “Oslo” May CTP available (Including Quadrant)

The "Oslo” team has released the third CTP of Microsoft’s forthcoming modeling platform.

Some of the  changes are:

For more detailed information check out the team announcement and the release notes.

New Installer

oslo setup

Empty Quadrant Workspace

empty quadrant

Intellipad Splitting

intellipad-multisplit And yes, I’ll be blogging about my web-layout DSL 🙂

kick it on DotNetKicks.com

Lang.NET and DSL DevCon (Seattle 2009)

I just got back from a good week in Seattle. My plan was to visit the DSL DevCon only, but it turned out that the cheapest option was to stay from Tue, 14th until Sun, 19th. I then had time to visit both Lang.NET and DSL DevCon as well as some friends in the area. Last time in Seattle (ALT.NET Conf) I was occupied with shopping only, but this time I also had a whole day for sightseeing. It was great!

Lang.NET (tweets, videos)

langnet Lang.NET was all about general-purpose languages. The talks were good and I met interesting people. This two tweets from Paul Vick (VB.NET compiler in person) and Amanda Laucher (F# MVP) pretty much sum up, what I felt most of the time:

vick paulvick: I hope someday to be as funny as Gilad or Erik Meijer.


panda-vick pandamonial: @paulvick Some day I hope to be as clever :) 


I left with a superficial (limited brain capacity) overview over F#, Tcl/tk (Eagle), CodeContracs, JVM internals, Axum and Links.

DSL DevCon (tweets, videos)

fill-your-head DSL DevCon (aka SellsCon) was initiated by Chris Sells. Both conferences were held in the Microsoft Research Building on their Campus in Redmond (close to Seattle).

I don’t yet know what to expect from the DSL hype. People have been doing DSLs for decades, as they did SOA. But who knows which story marketing starts telling about DSLs soon.

Still, I got my head filled up with lots of new useful information. Things I’ll have a closer look on will be Irony, F# and the Intentional Software. I’ll also follow up on all the good connections to super-interesting people. Was also nice to finally meet the Oslo guys Doug Purdy, Don Box, Chris Sells, Jeff Pinkston, Chris Anderson, Paul Vick and David Langworthy in person.

I’ll write follow-up posts about what I learned as soon as I have time for it.

What’s next?

I’m really tuned to see how our profession will evolve. I hope it will change dramatically. We need better processes, better integrated tools, closer communication of intentions and a significant productivity boost. I can’t believe that we will be able to create software so much faster. But, if our software wasn’t so closely tied to platforms and if it was written in a more flexible manner, so I hope, software could at least survive longer. Software is often dead born. That is, were our industry looses so much of it’s productivity.

dotnetpro: Kurzer Rede langer Sinn

Der erste Artikel der DSL-Trilogie bei dotnetpro ist raus 🙂

Titel: Kurze Rede langer Sinn –Domänenspezifische Sprachen in der Softwareentwicklung

Abstract: Mit wenigen Worten viel sagen; das ist das Ziel einer guten domänenspezifischen Sprache. Sie sind in Kundenprojekten
jüngst in Mode gekommen, um fachlichen und technischen Anforderungen besser begegnen zu können.

Ausgabe: dotnetpro 05/2009 (15. April 2009)

Autoren: Lars Corneliussen und Markus Völter

Ja, wirklich:

Bild 10

DotNetMagazin: Domänenspezifische Sprachen und Microsoft Oslo

Abstract: Auf der PDC letzten Herbst hat Microsoft eine neue Plattform vorgestellt: Oslo. Dabei handelt es sich um Frameworks und Tools zur Arbeit mit Modellen und der Erstellung von domänenspezifischen Sprachen. In diesem Artikel möchten wir einen Überblick über Oslo geben, und es in das Umfeld der modellgetriebenen Softwareentwicklung und der DSLs einordnen.

Download: http://www.voelter.de/data/articles/VoelterCorneliussen-OSLO.pdf

Publiziert in: DotNetMagazin Developer Channel, 03/2009

Markus Voelter, Independent/itemis, voelter@acm.org
Lars Corneliussen, itemis, lars.corneliussen@itemis.de

Fowler’s DSL example with MGrammar (Draft!)

I drafted Fowlers state-machine example with MGrammar. While doing so I found a few things I would like to see optimized or find better solutions for.

  • New line handling. I would like to express one required new line, when it is required, but then ignore all the others. Forum discussion.
    I could make new lines part of some tokens and then just interleave other tokens. But I don’t think this would be a nice solution. Any ideas?
  • The blocks events, resetEvents, commands and state+ have to be written in order. It is possible to describe a grammar where unordered blocks would be allowed, but it’s not trivial.
    Ordered and unordered “Lists” of syntaxes, separated somehow should IMHO be supported directly: forum discussion.
  • I wrote the Grammar using Intellipad and the three-pane input/grammar/AST view. It’s great! But I’d like to define the Semantic Model (using MSchema) along with the grammar and directly validate my AST against it: forum discussion.
  • References are not directly supported by MGrammar/MSchema. Forum discussion.
  • Xtext, which is quite comparable to MGrammar has a much more compact syntax. But I haven’t done a more deep comparison yet.
    Sven Efftinge’s Blog: Fowler’s DSL example with Xtext

Still missing:

  • A schema that represents the structure of the AST and validates it using constraints.
  • An adapter to Simple State Machine on CodePlex or a generating a state machine framework using T4.

Would love your feedback…

Grammar definition

module MGrammar.Net.Sample {

  // This is my first try, to parse the state machine
  // dsl syntax proposed by Martin Fowler
  language Statemachine 
    interleave Ignore = " ";
    syntax Main = 
        NewLines? e:Block(Events, NameAndCode)
        NewLines+ r:Block(ResetEvents, Name)
        NewLines+ c:Block(Commands, NameAndCode)
        NewLines+ s:List(StateBlock)
        => Statemachine 
          Events { valuesof(e) },
          ResetEvents { valuesof(r) },
          Commands { valuesof(c) },
    // list of syntax "Item" separated by one or more
    // new lines
    syntax List(Item) = n:Item => {n}
        | list:List(Item) NewLines+ n:Item 
            => {valuesof(list), n};
    // lists of tokens separated by whitespaces 
    syntax TokenList(Item) = n:Item => {n}
        | list:List(Item) n:Item 
            => {valuesof(list), n};

    // a block consisting of a keyword, new-line-
    // separated "Item"s and end
    syntax Block(Keyword, Item) = Keyword 
            NewLines items:List(Item) 
            NewLines End => {valuesof(items)};
    // a word projected as a name
    // grouped into a separate successor
    // for extensibility reasons
    syntax Name = n:Word
        => { Name {n} };
    // a word plus a code, separated by spaces
    syntax NameAndCode = n:Word c:Word
        => {Name {n}, Code{c}};
    // special block and subsyntaxes for states
    syntax StateBlock = State n:Word 
            actions:(NewLines a:Actions => a)?
            NewLines+ items:List(Transition) 
            NewLines+ End 
            => State 
                Name { n }, 
                Transitions { valuesof(items) } 

    syntax Transition = e:Word "=>" s:Word
        => { Event {e}, ToState{s} };
    syntax Actions = tActions "{" l:TokenList(Word) "}" 
        => Actions [ valuesof(l) ];
    // keyword specification for strong formatting
    @{Classification["Keyword"]} final token Events = "events";
    @{Classification["Keyword"]} final token Commands = "commands";
    @{Classification["Keyword"]} final token ResetEvents = "resetEvents";
    @{Classification["Keyword"]} final token State = "state";
    @{Classification["Keyword"]} final token End = "end";
    @{Classification["Keyword"]} final token tActions = "actions";
    // Some whitespace characters
    token NewLineCharacter 
            = 'u000A'  // New Line
            | 'u000D'  // Carriage Return
            | 'u0085'  // Next Line
            | 'u2028'  // Line Separator
            | 'u2029'; // Paragraph Separator
    token NewLines = NewLineCharacter#2..;
    token Letter = 'a'..'z' | 'A'..'Z';
    token Digit = '0'..'9';
    token Word = (Letter (Letter | Digit)*);

Input Text

  doorClosed  D1CL
  drawOpened  D2OP
  lightOn     L1ON
  doorOpened  D1OP
  panelClosed PNCL


  unlockPanel PNUL
  lockPanel   PNLK
  lockDoor    D1LK
  unlockDoor  D1UL 

state idle
  actions {unlockDoor lockPanel}
  doorClosed => active

state active
  drawOpened => waitingForLight
  lightOn    => waitingForDraw

state waitingForLight
  lightOn => unlockedPanel

state waitingForDraw
  drawOpened => unlockedPanel

state unlockedPanel
  actions {unlockPanel lockDoor}
  panelClosed => idle

Output AST


Open Letter to Douglas Purdy: Eclipse, Oslo, and how to invent the future together

(Find his answer here)

Dear Douglas Purdy,

Over the last several months I followed the development around “Oslo”. I couldn’t attend the PDC, but I watched all Oslo videos, read a lot of the reactions, and also spent some hands-on time writing a few schemas and grammars.

The subject I want to write to you about is particularly your talk A Lap around “Oslo” at PDC as well as your post What is Oslo?.

I’ll just quote some of your spoken and written words and put my comments below. Just for easier referencing I’ll group them in sections.

Feel free to answer on your blog in order to avoid endless comments. I suggest using the tag “Oslo2EMF”.

1. Preamble

I’ve been developing using Microsoft technologies for 7+ years now. I’m absolutely positive to Microsoft and I love .NET. Nothing here is intended to be disparaging about Microsoft.

We have realized that we live in a model-driven world.

Compared to the Java and Eclipse camps, I’d say, you realized that quite late, but still welcome and congratulations. Talking about models and particularly model-driven software development, they seem to be far ahead in both methodology and technology (more later). In a way MS also acknowledged this, by joining OMG [1]* after kind of criticizing it for a couple of years.

* see link index below for all following links

2. Terms

Now when we talk about models, and one of the things we talk about particularly with modeling inside of Microsoft, particularly with Oslo, is this notion of a very key term that I like to get across, which is Model-driven Development, Model-driven Software Development.

If you want to upset the community, just take an established term “B”, rename it to “A”, and then reinvent something slightly different branding it “B”.

My Point is that MDSD is an established term in the community. It has already been defined and there are several books available [2].

The term MDSD – as the community uses it – has its roots back in the OOPSLA in 2003 [3]. Many of the attendees did MDSD before that, but they didn’t have a term that wasn’t  trademarked (as MDA, MDD are). – Prove me wrong!

“This” MDSD stands for using models in the software creation and building process. In most cases this is done using code generation frameworks such as oAW[4] or androMDA[5].

In the Microsoft world MDSD was almost unheard [6], but Software Factories and the DSL Tools, as well as some Visual Studio built-in designers could be grouped into that category.

Now, in your talk, you renamed that approach to “model-assisted”. I think this is an appropriate term and I also understand your next point about “model-driven” in the sense of models directly executed by runtimes. But in that sense, “driven” means to drive applications and runtimes, not the development process.

To make my point: Please don’t call executing models MDSD. I think Model-driven Applications, as you also call it sometimes and as written on the slides (14:50), too, is more adequate.

3. Runtimes vs. Code Generation

To stick to your terminology, you said model-assisted development is a great way of creating software today. I do totally agree with that.

And you see some great examples on that on the slide. One of the canonical ones is HTML.

You are right. HTML is a model which is driven by several runtimes and it’s even openly specified. But it’s also an great example of how hard it is to write runtimes – All browser vendors struggle – I guess, I don’t have to say more here.

Another “great” example is the Windows Workflow Foundation. I like it. I even gave talks on it. Microsoft did well, but not good enough. They have to rewrite the runtime, the tools, …

Textual DSLs – I tell you this thing is hot!

Exactly! I totally agree, and I love MGrammar.

Q: “10x more productive with Oslo than with their current set of tools” to do what?
A: To write an .net application.

We are giving you mservice, mweb, etc.

You can, of course, write your own DSL, but we think that that will be the province of mainly ISVs and people that write frameworks today.

I totally disagree. Do you really mean what you’re saying?

DSLs are broadly used in projects, not only frameworks. You’ll miss quite a bunch of (growing) audience, if you focus only on ISVs. Big companies do big projects. And there is written millions of lines of code in such projects. MDSD, already today, boosts productivity in such projects – not 10x, but still a lot. [9]

I don’t say, runtimes are bad. But it is just not realistic to create runtimes for everything you want to base on models.

One of the reasons code-generation has so bad reputation – especially in the MS world – is because it’s often too ugly. When I talk about code generation, I mean generating well-structured, nice formatted high-quality code.

For now, Microsoft’s only answer to code generation is T4. Nice, but usually it leads to ugly code. It doesn’t even support creating multiple files for different classes.

What do you think? Do you have any plans on leveraging a code generation framework?

4. Open Microsoft and the Eclipse Modeling Project

Early, open and often. This is Pre-Pre-Pre Alpha, its raw. We want to get your feedback.

Love it!

M will be released under the Microsoft Open Specification Promise(OSP)

Does it mean, the source code will be published as a reference implementation, too? And what is M? MGrammar, MGraph, MShema, MWeb, MService, …? Will the mapping to the repository, and the definition of the repository be opened?

Anyone can implement it. We want this approach wide spread on a variety of different platforms. We want it to be as broad as Xml is today.

Quite ambitious. Where is the standards consortium, then? What about JSON?

We want to engage, particularly with the Open Source Community, in order to make sure that we can invent the future together.

I’m quite interested in what that engagement could be like, when it comes to investing effort or money.

Are we going to do anything to build a bridge to EMF, ehm, the answer is: …. ehm, we will see.

The key thing is: What I’d love to see is, I’d love to see the Eclipse Model Project, I’d love to see that community to come up with a bridge for this. So that’s part of the open – I’m not kidding.

So if they want to develop a bridge for this, absolutely I’m going to support doing that. That’s one of the key reasons we do the OSP.

I’d love to see an Eclipse “M” Project. I’d love it.

Could somebody quote me on that, so we can get that ball rolling?

Quoted. So now lets get the ball rolling. We’ve got two points here. Who is “that community”, and what kind of “bridge” do you mean?

I don’t think, Eclipse just throws their well tested products away in order to use “your” pre-pre-pre-alpha code. Asking Eclipse to implement “M”, at the first glance, sounds arrogant and kind of ridiculous to me.

But, being open, lets imagine EMF was a place and we want a nice bridge to and from Oslo.

Of course there will be the feeling of competition…
But in the end, the success of modeling is the most important thing.

Ed Merks, EMF project co-lead

Where to build the bridge? And what to archive with it?

  1. EMF (Ecore) <-> MGraph/MSchema
    If you understand both models on both sides, you’ve won alot. But mapping the schemas to Ecore could be a hard issue. EMF uses explicit inheritance, while MSchema uses structural subtyping. But still, it could be done.
  2. xtext <-> MGrammar
    Both languages transform unicode to semantic models. The concepts match, while the syntax is quite different.
  3. TBD, T4? <-> openArchitectureWare
    When it comes to code generation, M2M transformations and model checks, as said before Microsoft doesn’t offer anything even approaching openArchitectureWare.

I think the people you should get involved with are Ed Merks (EMF co-lead and Ecore-developer) as well as Sven Efftinge(xtext and oAW Project lead),  Markus Völter (xtext, oAW) and Peter Friese (xtext, xtend, oAW). [7]

Could you imagine an open space conference on this collaboration? You say “I’d love it” so often that I have to ask, how much would you love it?

Sincerely yours,

Lars Corneliussen

Links Index

Since this is a letter, I didn’t want to confuse it with links. So I indexed them and put them below.

What "Oslo" is and is not (November 2008)

See also: Open Letter to Douglas Purdy: Eclipse, Oslo, and how to invent the future together

The PDC is over, and most contents including the Oslo SDK (without Quadrant) and all PDC Session Videos on channel9. Thanks! But where are we now? If you want a “brief” overview, you should at least have a look at A Lap around “Oslo”.

Jump to “What Oslo definitely is!”

Oslo Resources

What Oslo is not!

I’ll start with correcting some of my former assumptions in DSL Tools, T4, the Software Factories and “Facts” Rumors about Oslo.

Built upon DSL Tools?

No, Oslo (M and Quadrant) is not built upon DSL Tools, T4 and the UML Tooling in Visual Studio 2010. It’s totally apart. The DSL Tools are the here and now, while Oslo still is “Pre-Pre-Pre-Alpha” (Douglas Purdy).

Douglas promised that his team is working tight with the VSTX team in order to bring this together. He mentioned the possibility of using M as the backing metamodel format for the DSL Toolkit. Graphically edited DSLs could then be converted, described in MSchema and stored into the Oslo Repository or MGraph files. Update (12.Nov): Later in his talk “a lap around Oslo” Doug also said his the team is discussing to schematize the DSL Toolkit, and let the graphical DSLs live within Oslo.

A move towards UML/OMG?

No. I don’t think so. Microsoft joined the OMG and they support some UML Diagrams in Visual Studio 2010. But so far this has not to do much with Oslo.

Update (12.Nov): Someone asked about how Oslo relates to XMI and UML. Doug’ promised that they will model the UML-Domain and let the UML Designers in Visual Studio live within Oslo.

Talking of Model-driven Architecture (MDA) it seems that Microsoft avoids this abbreviation. They rather talk about Model-driven Development and Model-driven Applications – I’ll write more on this in a separate post.

A Application/Process Server?

Dublin is announced to be Model-driven, but it is not a part of “Oslo”, but rather related to Windows Azure and IIS. The plan is to host cloud-enabled services both locally on Dublin and in the cloud on Windows Azure with maximal control and minimal effort for deployment and configuration.

Read Workflows, Services, and Models by David Chappell to see how Dublin relates to Oslo.

A new Version of WF and WCF?

WCF and WF were model-driven right from the beginning, but in the next versions the source for the models that drive Workflows and Services might come from Oslo.

MService is a textual DSL that combines service configuration, implementation and workflow definition into one resource.

What Oslo definitely is

A new Modeling Language Family

Yes, it’s definitely about a new modeling language family “M”, consisting of three core languages. These languages do all have similar Syntax and a shared type system.

  • MSchema
    Defines schemas for data instances. Quite comparable to XSD and DTD.
  • MGraph
    JSON-like format for capturing concrete data instances.
  • MGrammar
    Defines grammars for textual DSLs. Could also be looked at as a Unicode-to-MGraph-tranformation language.

There are other languages planned for some horizontal domains as Database, Services and Web. But here you can even put some more “Pre”s before the “Alpha”.

A Language Workbench for textual DSLs!

Well, I’ll just copy Martin on that.

At some point I really need to rethink what I consider the defining elements of a Language Workbench to be. For the moment let’s just say that Xtext and Oslo feel like Language Workbenches and until I revisit the definition I’ll treat them as such.

Martin Fowler Bliki: Oslo

A new Storage Repository!?

Oslo Repository is a tool and a framework that allows storing models into SQL Server.  I’m still quite torn on this idea.

  • Design-time story: Many tool vendors tried backing repositories supporting simultaneous changes. But sharing them in files is just easier. If it was on the web – ok, then we had to talk about security and stuff – But as it is tied to SQL Server 2008, it looses a lot of my attention.
  • Runtime story: Having models in a database at runtime at least seams more natural in my opinion. What then to store there is another thing to figure out. Is it meant to store operational data or configurations and application definitions? That’s what is left to the customer to decide.

The repository compiler (mx.exe) generates T-SQL code out of your models, while it supports two modes:

  • Plain T-SQL: Mapps your explicit MSchema definitions or implicitely “guessed” schemas from MGraph data to data tables.
  • Repository SQL: A Repository is a database pre-populated with tons of schemas describing the “Microsoft IT world”. It also supports some core services, as are:
    • Deployment: Import and Export from and to M + Webservice Deployment to Dublin
    • Security: Tables hidden behind views, claims-based security
    • Catalog: Keeps the semantics you have in your MSchema as not everything maps directly to T-SQL.
    • Versioning: Sadly not instance data versioning. But you got full SQL Server 2008 capabilities including SSIS, Change Tracking, Replication, … + Due to the separation of views and tables you can support backward-compatible schema evolution.

Oslo does not come with a own data-access technology stack. It rather gives you a generator for EF-Models.

A Graphical Modeling Toolkit!

Yes. Quadrant lets you interact with models graphically. It’s highly generic, customizable and it looks great.

But as I’ve understand, Quadrant only works on models stored in the Repository, hence SQL Server. Really interested to see how this works together with your textual definitions you might rather store in Version Control.

Release Dates, Packaging and Pricing

From Microsoft “Oslo” Frequently Asked Questions

Q: What is the timeline for shipping “Oslo”?

A:  We are not disclosing the release schedule at this time. We are committed to releasing regular Community Technology Previews (CTPs) after PDC and will engage with the developer community on an on-going basis. The Oslo Development Center (http://msdn.microsoft.com/oslo) will also be the place to learn about the latest Oslo-related downloads.

Q: Is “Oslo” shipping with the rest of the Visual Studio 2010 product line?

A: We are not currently disclosing schedules or packaging.

Einführung in die Windows Workflow Foundation (V 3.5)

Auf der NRW08 hatte ich eine Präsentation zur Windows Workflow Foundation gehalten – zugegeben etwas verspätet ist diese nun online verfügbar.

In diesem Talk sind die Änderungen, die für WF 4 zu erwarten sind nicht berücksichtigt. Die Arbeitsweise in WF 4 bleibt die gleiche, laut Ankündigung sollten aber signifikante Probleme behoben und, was ich besonders bemerkenswert finde, das Erstellen von eigenen Aktivitäten sowie die Integration mit WCF deutlich vereinfacht werden sowie.