XOTcl is included in the Windows distribution WinTclTk.
It includes XOTcl-related packages:

• XOTcl v1.5.3
  
• xotclexpat
• xotclgdbm
• xotclsdbm
• additional XOTcl libraries (e.g. xml, storage, etc.)
  
• XOTclIDE

The distribution is available under the following URL:
http://wintcltk.sourceforge.net

A single-file wrapper with XOTcl support is available, too, see URL:
http://wintcltk.sourceforge.net/tkwrap.html