FAQ Are there any special Eclipse UI guidelines?
A wealth of Eclipse UI guidelines exists. Mentioning any in this single FAQ would seem to do no justice to Nick Edgar, Kevin Haaland, Jin Li, and Kimberley Peter. Please refer to their online Eclipse article “Eclipse User Interface Guidelines.” In their seminal work, they brush on such topics as icon sizes and color palettes, wizards, editors, dialogs, commands, views, perspectives, windows, properties, widgets, navigators, tasks, preferences, outlines, properties, bookmarks, text editors, the flat-look design, accelerators, best practices, and a checklist for developers.
In fact, the 100-page article is a great source of inspiration for any plug-in developer. Study it before you create any Eclipse plug-in with a visual representation to avoid mistakes made by others and to learn from the experts how to design high-quality UI designs.
Online article on UI Guidelines (http://eclipse.org/articles).
There is a partly obsolete article with eclipse 2.1 UI Guidelines: 
This FAQ was originally published in Official Eclipse 3.0 FAQs. Copyright 2004, Pearson Education, Inc. All rights reserved. This text is made available here under the terms of the Eclipse Public License v1.0.