We have now some estimates for the last two planned “feature freeze exception” features.
Seth posted about the python API. “We are almost there”, although I won’t try to interpret that exactly.
In another thread Qbort told that curves in polygons may be ready within a couple of weeks.
In real life we may have these available within a month or more, but even with well educated realism there’s a good chance that within some weeks, not months, we will have all features there and only bugfixing is left.
In yet another mail thread Wayne revealed that he wants v6 out within 3 months or less. That would really be something!
Of course the real schedule depends partly on bug reporting. It would probably be better to find and report all bugs at once rather than one by one over time. The more users adopt 5.99, at least for testing purposes, the better. It’s still buggy, but if someone can take a risk of some lost work hours and can recover from data loss 5.99 is soon ready for non-critical work.
Curved polygons is the last feature which affects the file format. There’s still a very small possibility for bug fixes for the file formats; othewise the nightly builds will soon be both backward and forward compatible with other nightly builds from day to day, so it should be possible to downgrade to work around some newly introduced bug.