I guess it sort of depends on how you define "success"; there's plenty of projects that still have some development and active users.
TeXMacs was release in the late 90's (I think) and it's pretty neat and I think has at least some user base, and I think GNU Parallel was released in the mid 2000s and I know a number of people who use that (including myself).
TeXMacs was release in the late 90's (I think) and it's pretty neat and I think has at least some user base, and I think GNU Parallel was released in the mid 2000s and I know a number of people who use that (including myself).