This is a visual studio project that we're using at Gist. We build this as a
static library that we include into our Outlook plugin.
You will need to get the xulrunner-sdk (2.0), available from:
https://developer.mozilla.org/En/Gecko_SDK
or from the Mozilla hg repo http://hg.mozilla.org/releases/mozilla-2.0/
We look for it in ../external/xulrunner-sdk subdirectory.
Only real difference between this and the below original mozembed project is
the added support to directly specify the path to xulrunner in the call to 
InitEmbedding.

This is a copy of https://wiki.mozilla.org/Embedding/NewApi/Win32
The main repository is in:
hg clone http://hg.mozilla.org/incubator/embedding/ mozembed