In the preferences one can switch on (or off) compression and in Bl 2.49 there is a big reduction in needed space. (from about 400 KB .blend to about 50 KB)
In Bl 2.53 SVN 31574 a blend with only the default Cube the saved .blend does not change size with or without compression? (stays around 452 KB)
Is it a bug or something else a missing ‘switch’ in user-config.py (for self compilation)?
But see bl 2.49 even with more or less empty screen the effect of compression is a factor of nearly 10 less .blend file? Why not anymore in Bl 2.53?
If ca. 450KB is mimimum … one should know…