It's an unfortunate fact that many Eclipse projects operate in their own little worlds without knowledge of or collaboration with other projects. This leads to code duplication and visible seams in the finished Eclipse product. Part of the problem is social. It's hard to keep track of all the projects out there and even harder to reach out to discuss collaboration, but a big part of it is also due to the lack of infrastructure that facilitates code sharing efforts. Consider the situation where two sibling projects (no dependency on each other) want to collaborate on some shared code. There is really no effective way for this collaboration to take place. Where would you put the shared code?
In order to try to address this problem, I have been working a proposal for Eclipse Nexus Project that would take on facilitating such collaboration. Right now, I am discussing the draft proposal with the Eclipse Technology Project PMC which would serve as a host for Nexus as it gets off the ground.
Anyone interested in learning more or in joining the effort can read the draft proposal, add themselves to the wiki, contact me directly, etc.