- Improved performance on intensive maps.
- New and improved sound system supporting reverb effects on all sound cards, not just Creative Labs'.
- SPC is now a first-class music format that no longer requires an external DLL to play.
- Supports the UDMF map format.
- Text-based texture definition format.
- Supports Vavoom's vertex height things.
- Supports Eterity's 3DMIDTEX lines.
- Supports linked sectors, to ensure that multiple sectors can move consistently in sync.
- More compatibility options, and automatic selection of those options for selected maps that require them to be playable.
- New DECORATE features, including better error reporting.
- Freedoom, Chex Quest, and Chex Quest 3 are recognized as IWADs and can be selected in the IWAD picker dialog box.
- New ACS features.
- New SBARINFO features.
- Various and sundry bug fixes.




