UCINET 1.0. In the early 80's, Lin Freeman collected together a set of network analysis programs written by different people and put them together in a set of diskettes with documentation. The programs were written in a variety of languages and had different input and output formats. 

UCINET 2.0. In 1985, Lin Freeman wrote a common BASIC front-end for all the programs in the UCINET suite. The front-end would translate the user's input into the format required for any given program, and then execute that program. 

UCINET 3.0. In 1987, a post-doc named Bruce MacEvoy translated all of the UCINET programs into a single integrated BASIC program, adding numerous options and capabilities. 

UCINET 4.0. In the late 80's, Steve Borgatti wrote a suite of network analysis programs called NETPAC. The programs were written in Turbo Pascal, and made use of modern data structures and graph theoretic algorithms. The NETPAC programs were relatively fast and could handle larger datasets than UCINET. Lin Freeman suggested that rather than have competing programs, we just turn NETPAC into the next version of UCINET. So the user interface of NETPAC was reworked to look more like UCINET, and UCINET IV was released in 1992. 

UCINET 5.0. In 2002, the DOS version of UCINET was converted to Windows 95.