The greatest tasks that need to be done, in order of priority:

For version 0.301a:

1.  Gcc port.
2.  In-code documentation.

For version 0.310a:

3.  Block AI system and genetic AI algorithms.
4.  Renewed god system.
5.  Traps.
6.  Identify system.
7.  Player races and classes.

For versions after that:

8.  Bodyparts.
9.  Wishing parser.
10. Skill system.
11. Magic system.
12. Dungeon water tiles and swimming.
13. Wilderness encounters and other similiar events.
14. Random towns, dungeons and quests.
15. Intercontinental transportation.