Slickgrid was built by Michael Leibman (GitHub @mleibman) over several years from 2010 to 2013.
Ben McIntyre (GitHub @6pac) was for a while the most active maintainer of the project on his own fork as a deliberately non-customised build, keeping the core of the project current supported by the SlickGrid community.
The project has been kept up to date with the latest builds of jQuery and jQueryUI. Targeted enhancements and bug fixes have been applied.
@GhisCoding has recently been the most active contributor, with major updates to core code. He has several of his own GitHub repos that layer features on top of the 6pac SlickGrid repo.
There have been many minor contributors. Everyone is enshrined in the log history!