Oh, what's DXCore? For review, DXCore is...
DXCore, the base software that both our CodeRush and Refactor! Pro products use, available as a free download. Essentially, DXCore wraps the somewhat-difficult-to-use VSIP interfaces in a neat .NET package with extensibility points, and also provides some extra functionality for Visual Studio available nowhere else. Using DXCore, you too can make some rather nifty tools for Visual Studio that use the same visual effects we use in CodeRush and Refactor! Pro. We provide some documentation for this, but we also have a very active newsgroup for DXCore on our server, and there's even a community site that supports development using DXCore.» DXCore: more wholesome goodness
I've tried to build a DXCore plug-in myself... it's quite a challenge getting up to speed. There are some great resources, like a DevExpress newsgroup dedicated to plug-in development, as well as an episode on dnrTV where Mark Miller (architect with DevExpress) walked through building a plug-in with the DXCore. What's really lacking are people writing ABOUT their experiences in building plug-ins. I think if we saw more of these, we'd see more plug-ins being developed.
The post by Julian is fantastic... problem is there aren't enough of these! It's a great read... hopefully Julian will get some good feedback to keep doing more of these.
Another undercurrent in the newsgroups is people are a bit frustrated there's no single directory for DXCore plug-ins. Someone setup a SourceForge project (CRPlugin) to host them... but no one seems to use it. Some guys have their own pages of their link collection (like Jay Kimble) plug-ins, like Rory Becker and Travis Illig's software category. I am tracking all the ones I find with a tag on my del.icio.us (link below)... all we need is a DXCore Wiki!