Complex sentence: Development of Mathomatic was started in 1986 by George Gesslein II. It was originally written in Microsoft C for MS-DOS and released as shareware with a graphing program.
Split into simpler sentences: Development of Mathomatic was started in the year 1986 by George Gesslein II. It was originally written in Microsoft C for MS-DOS. Afterwards it was released as shareware with a graphing program.