'''Optimized Systems Software''' ('''OSS''') was a company that produced [[disk operating system]]s, [[programming languages]] with integrated development environments, and applications primarily for the [[Atari 8-bit family]] of home computers, but some products were also sold for the [[Apple II]].<ref name=finest/> OSS was best known for their enhanced versions of [[Atari BASIC]] and the [[MAC/65]] assembler, (both of which are much faster than Atari's products), and the [[Action! (programming language)|Action!]] programming language. OSS also sold some products for the [[Apple II]].<ref name=finest/>
OSS transitioned to other16-bit platforms with Personal Pascal for the [[Atari ST]]<ref name=ppmanual>{{cite web|title=Personal Pascal for the Atari ST Manual|url=https://archive.org/details/OSSPersonalPascal|website=archive.org}}</ref> and Personal Prolog for [[Macintosh]] (which was also advertised for the Atari ST, but may not have been released). OSS was not as significant in those markets.
