Within kubuntu (or ubuntu derived setups) you can have a moonlight development .. aka the silverlight open source version that will run on linux.
if you install the
monodevelop-moonlight
and also the
monodoc-moonlight-manual
packages, the last one is the manual if you need some help, but the first one will allow the monodevelop development environment have the moonlight plugin which creates a project to develop silverlight applications in.