Patch 1.0.3

[Maul]

In Brood War they just added a letter for hot fixes I believe

[GRUNT]

I always thought that the login screen needed a buff!

[TheRabidDeer]

In Brood War they just added a letter for hot fixes I believe

This is correct. BW used a 2 number system (and minor patches just added a letter). I think WoW was the first Blizzard game to use the 3 number (technically 4 number) system.

a.b.c.d

a = Major
b = Minor
c = Revision
d = Build (basically this is how many times they hit save to produce this specific version)

So, since we are in just plain old SC2, we are Major version 1
We havent had any big changes like balance or chat features or anything like that, so it is version 0
We have had several minor changes like bug fixes, so we are at version 3 now.
And the build number is 16291 (they saved the current version this many times, most development software has this built in to auto-increment on save)

The build number will probably reset with the release of a new balance patch that would increment the minor number.

WoW has followed this same scheme.

Do note, however, that you can have version 1.10.1, it doesnt go from 1.9.1 to 2.0.1