From the intro:

Wild Fire, or WF, is a table top miniature wargame for 10-30 mm figures. It is focussed on reinforced platoon level skirmish games, and is suitable for one off games, or campaigns, but can be used to play games as small as squad size. It uses the same system as Baptism of Fire.

It's been reprinted together with the WWII rules in Baptism of Fire II.