Keith Short's Blog : DSL Tools

Comments on Communication Between Doug Purdy and Lars Corneliussen

Keith Short — Tue, 18 Nov 2008 22:37:00 GMT

Doug has published a response to an Open Letter addressed to him from Lars Corneliussen. I think Doug did a good job in addressing Lars’ concerns, and where not, to invite discussion. I wanted to add a couple of comments of my own.

First: terminology connected with modeling, code generation and runtimes. Given my background in various modeling efforts at Microsoft over the last ten years, I know of the difficulty in seeming to redefine established terms. We faced a lot of the same concerns when, in 2004, we tried to help people understand the subtle distinctions between modeling with DSLs and using UML. As history showed, in many cases we were not very successful then, though these days (see several entries on Steve Cook’s blog especially this one and this paper from Andrew Watson, Technical Director at the OMG), most people are willing to see how both approaches may combine to bring benefits to developers across the lifecycle.

I for one have been using the term “model-driven software development” (or just “model-driven development” for short) for a number of years (actually going back to my pre-Microsoft years at Texas Instruments during the era of CASE tools). When Jack and I wrote the Software Factories book, we used the term model-driven development to encompass both “model-assisted” and “model-driven” as Doug uses those terms. We saw then, and still do today, that MDSD could involve models that transform to other models, which transform to code and which just “complete frameworks” by transforming into whatever is necessary (including no transformation) to drive a framework at runtime. For example, if I use a transform to build a logical data model, several workflows, and some service descriptions from a set of business process models, I think I’m doing more than just drawing, and I may be doing some code generation and model generation. Which of the three terms best describes this activity?

As I explained in my previous blog entry concerning the DSL Toolkit and Oslo, we are trying to help folks understand the specifics of Oslo in its first incarnation, with respect to pre-existing technologies from Visual Studio (and other parts of Microsoft). This leads us to seek terminology that helps us conduct that discussion, and in cases such as this, involves some subtle distinctions that are tough to differentiate. As Doug says: “when you a birth a new product, naming/terminology is often the most difficult aspect of the process”.

Second: Open Microsoft and Eclipse Modeling Project. I second Doug’s remarks wholeheartedly. I’d especially like to see discussion on relationships between EMF and oAW technologies.

Oslo and the DSL Toolkit

Keith Short — Fri, 07 Nov 2008 01:30:00 GMT

I’ve received a number of questions concerning the relationship of Oslo to the Visual Studio DSL Toolkit. Comments have varied from the sublime (see David Ing’s comment on his blog “My best guess is that the DSL Toolkit is research road kill in front of the big Oslo truck and that VSTS Architecture Edition was just about a necessary cycle too early”) to the ridiculous. Since I’ve been a founder member of both projects, I thought I’d try to start the discussion with a few comments of my own.

Firstly, it’s true that the two efforts are built on different technology stacks – the DSL Toolkit works on file-based artifacts (schemas, model instances, etc.) and produces graphical and forms-based tools that run as add-ins to Visual Studio – dramatically simplifying the task of creating tools hosted via VS extensibility.

On the other hand, Oslo is based on an underlying SQL database. Quadrant depends on the underlying database for both the data it is processing and its own configuration data. In other words, Quadrant’s equivalent of the DSL Tools’ domain modeling language and the shape and shape mapping languages is MSchema. Concrete textual languages are of course defined in MGrammar.

Despite these differences, two things need to be made really clear:

1. Both the Oslo and the DSL Toolkit have grown from a common belief in the role DSLs can play in the development lifecycle. Not just during development, but DSLs that help record Business Objectives, Business Processes and Entities, System Architectures, Software components and connections, Deployment Information, Data Center Configuration, and System Management to name just some of the lifecycle stages. This is a shared vision, well documented elsewhere, though each project has focused on a different aspect initially. The DSL Toolkit builds great graphical (box and line) tools that run in Visual Studio and may be translated into code-based artifacts. Oslo is focused on textual and graphical developer experiences around models that initially represent code and configuration that “completes” the underlying frameworks that are part of the application platform – in other words – models that are mostly executable by the underlying servers and frameworks (e.g. WF, WCF, and Identity Services).

2. Both products have a lifecycle in front of them. The two teams, already aligned around vision, are working together to bridge differences over releases. Would it have been nice to have gone dark for a period while we resolved these technology stack issues and re-emerged with a fully aligned set of technologies? You bet – but such a strategy rarely ends with the right thing being built for customers. Ideas we are tossing around include (a) storing DSL Toolkit artifacts (including those created with the emerging UML tools from VSTA) in the Oslo Repository, (b) using MSchema as the domain language for the DSL Toolkit, and (c) converging on a single way to specify concrete DSL syntax whether it is graphical or textual. Sadly, I can’t give dates at this point.

Stuart Kent is the architect for DSL Tools. If you take a look at Stuart’s blog, you’ll find the latest blog entry where he responds to the same questions from his point of view.

Yet Another Promise to Start Blogging !!

Keith Short — Sat, 25 Oct 2008 02:10:00 GMT

Yet again, it’s been a long time since I wrote to my blog. This posting is my restart.

I know, you just have to look at the last posting of over two years ago to realize I’ve said that before!

But here’s what happened. Shortly after writing that last posting, I moved from Visual Studio to join the group that was working on the earliest ideas that have now become known by the codeword “Oslo”. Obviously we couldn’t talk about this work, but now, at last, we are about to make the project public in a *big* way at next week’s PDC. You just have to look at blogs such as Don Box’s or Doug Purdy’s to realize “Oslo” is Microsoft’s modeling platform consisting of a new language for describing models and DSLs, a database in which to store models of various kinds, and a new tool to view and edit them.

I’ve mostly been working on the design of the model store (a SQL Server database) and using the new language to create schemas for the new store, but I’ve been able to bring a long background in model driven development, software factories and DSL tools to help with the design and testing of the language and tool.

For me this is very exciting since the “Oslo” investment represents a serious commitment from Microsoft to change the game and make modeling mainstream. That’s almost been the story of my life!

Once the excitement over the various announcements that will be made at the PDC subsides, I’ll try to give more background from my perspective, and begin the task of helping folks understand exactly what we are doing in this space.

New Website for Software Factories

Keith Short — Sat, 21 May 2005 01:55:00 GMT

Although I have been lax at blogging again this last month, the team has been extremely busy with the various efforts around Software Factories. In the course of the last few weeks we have opened a new public portal that will become the focus of all activities under the umbrella term of the Microsoft “Software Factories Initiative”. You can visit this site at http://lab.msdn.microsoft.com/teamsystem/workshop/sf/default.aspx .

You notice that on this site we’ve placed links to the two software download sites for the DSL Tools and for the Guidance Automation Toolkit (GAT). Some of you may be familiar with the DSL Tools (visit the blogs of Steve, Stuart, Alan and Gareth for details) but less familiar with the GAT. Please check-out the article that describes what the GAT is used for. In a forthcoming posting, I’ll explain how the GAT forms the second of three chunks of technology that constitute our initial implementation of basic Software Factory functionality in the Software Factories Initiative.