It's just Firefox with:
- Privacy settings (gathered from IceCat, pyllyukko, gHacks)
- Build options
- Iceweasel branding
- Own profile location %USERPROFILE%\AppData\Roaming\Debian\Iceweasel
- Video playback support for video/x-matroska mime type, patch.
Some videos require automatic playback.
Go to Options -> Privacy & Secure -> Autoplay Settings, then set Default for all websites to Allow audio and Video.
To check and download the latest version, use menu Tools -> [GIT Releases] Download the latest version
Launcher start.exe is created in Bat To Exe Converter. Some antiviruses may react on it.