HelpGear
CHM, Web Help, and PDF creation is easy with an excellent help authoring tool
CHM Editor
handy wysiwyg editor which can be used for editing and translating chm files.
CHM OwnerGuard
drm, security, copy protection and watermarking solution for chm documents
HelpNDoc
help authoring tool producing chm, html, pdf, word, epub, kindle documentation
Aml2CHM
plugin for creaion html help files (chm) from aml pages documents