PaulB

Microsoft Help/CHM is certainly still supported--I'm a tech writer and my firm is still using this format. In its defence, it integrates with Visual Studio for context-sensitive help, it works offline and everything is packaged into a single file. But there's really no good reason to continue with it--even if your criteria is offline support, you can create something far more sophisticated with HTML 5 and JavaScript. Programs like Jekyll or Hugo make this relatively straightforward.