server.bat and developer.bat have a -Xmx256M. I always crank up this max to 512 or 768.
Also, Developer caches all the stuff (DocumentTypes and Flows) that are opened inside it for the session. There is a preference to get it to start tossing stuff, so if you have a few large things you can load them without getting an OutOfMemoryException.
HTH,
Fred
#edi#webMethods#Integration-Server-and-ESB