I finally created a github repository for ikdasm. A couple of weeks ago I fixed some ildasm compatibility issues and changed pinvokeimpl and marshalas handling to use the IKVM.Reflection specific APIs instead of decoding the pseudo custom attributes (I also used the new IKVM.Reflection feature to disable generating pseudo custom attributes). I added external module support and fixed some other small issues.
The primary purpose of ikdasm is to make sure that the IKVM.Reflection API is complete. I believe it now exposes all relevant Managed PE file features. The secondary feature is to test IKVM.Reflection and to make this easy ikdasm replicates (almost) all ildasm quirks to enable comparing the output files. I disassembled a large number of files (including C++/CLI and Managed C++ files) and compared the results.
Only a small subset of ildasm functionality has been cloned. There is no GUI and most command line options are also not implemented.
Pull requests are welcome.