This puts it out of reach for many ruby developers deploying to a Windows environment without an installed C compiler. In the past I’ve leaned on a few good Samaritans that posted pre-compiled versions, but unfortunately most of these have either been taken down or are really old.
So, in desperate need of an install on a new windows VM I just built it from source. If you trust our binaries you can download the gem-ified ruby-ldap build based on the latest 0.9.7 release and compiled using Visual Studio 2008.
gem install ldap-0.9.7-mswin32.gem
I’ve tested this on a few boxes, though your mileage may vary.