Hu, I was surprised at read-only mode...
Anyway, I know many program uses even-odd version numbering, like linux kernel 2.x.
[major version].[major revision].[minor revision]
If major revision is odd, it's unstable version.
But in wikipedia page, it says that gcc 4.9.0 is stable version.
Does NOT gcc uses that version numbering? But I've heard that gcc 4.7 has many bugs, so I can't make sure..