Your users all can run the FireFox browser on MS-Windows and you want very fast XForms loading.
The Mozilla Firefox Plugin
This plugin was developed over several years with the support of IBM and Novell. Around 2009 the support for it has been in doubt but there are still active updates.
The official version is available from addons.mozilla.org.
Nightly and other (testing) builds are available at Philipp Wagner's Web Site
- Mozilla FireFox XForms page Note that this web page was last updated in October 7th, 2008.