Oostendorp was a contributor and content editor of Slashdot as well as an author of the SlashCode software—Slashdot's freely licensed technological platform.
[citation needed][1] In addition to his work on Slashdot, Oostendorp's work at BSI included the creation of the early online encyclopedia project Everything2,[2] and the Perl programming web community PerlMonks which used the Everything Engine.
After the sale of BSI to Andover.net and subsequently to VA Linux Systems (which became Geeknet), Oostendorp worked as a developer and manager at the free software and open source hosting platform SourceForge.
While at Michigan, he published several academic papers based on his experience with online communities.
[3][4][5] Oostendorp founded the Ann Arbor, Michigan-based Internet of Things startup Sight Machine[6] (formerly Ingenuitas) focused on industrial applications of computer vision techniques.