The first version of OS/2 was released by IBM in December of 1987. Supposedly it was nearly complete in 1986 but a decision was made to delay the release, so that IBM could release the PS/2. Strong comparisons were made with DOS, but there were major differences, as well. For example, the command line and familiar commands were common to both. But, the internal workings of OS/2 had brought in features that were never before offered on a PC. The lead architects of OS/2 were Gordon Letwin, from Microsoft, and Ed Iacobucci (who would later be the co-founder of Citrix) from IBM. Because of time restraints, not all features were released on 1.0, most notably being the Presentation Manager, the installable file systems and the named pipes.