MDA versus MDSD

from : http://www.openarchitectureware.org/forum/viewtopic.php?showtopic=9124

"MDA does not mean that you need to have UML models. Its only one way and sometimes not the best. Further, forget about the MDA spec. It is even no specification at all, its only a "guide". And it does not work as the MDA people think. Best practices in model-driven development are to not conform to MDA, so we call this MDSD. It might be that your process is more or less like MDA suggests, but you will only be successful if you break MDA concepts.
This is a long story...

Karsten Thoms"

Xtext and Java VM configuration

By developing DSLs with Xtext one usually work with two Eclipse workbenches:

• one by design-time containing three projects: the grammar, the DSL-editor and the generator,
  
• and a second one started from the first where the three DSL-plugin are deployed.
  

In order to avoid PermGem space problem it is important to configure properly the VM where the second runtime-workbench is started. A good setting is:


-Xms256m -Xmx512m -XX:MaxPermSize=256m

If you are working on Max OS you will possibly get the following errors : "Cannot load 32-bit SWT libraries on 64-bit JVM". To fix the problem I use the following VM parameters:

-d32 -Dosgi.requiredJavaVersion=1.5 -XstartOnFirstThread -Dorg.eclipse.swt.internal.carbon.smallFonts -XX:MaxPermSize=256m -Xms256m -Xmx512m -Xdock:icon=../Resources/Eclipse.icns -XstartOnFirstThread -Dorg.eclipse.swt.internal.carbon.smallFonts