Ron Vogl writes:

I did an internship at Microsoft in the summer of 1997, and at that time, Microsoft had two source-code control tools in use.  Some groups did indeed use source-safe.  The Outlook group, of which I was a temporary member, used an internal Microsoft tool called Source Library Manager, abbreviated SLM and pronounced either slim or slam depending on how you were feeling about it.  SLM was command-line only, with a mix of SourceSafe- and CVS-style workings.  From what I could gather from the interns in other groups, SourceSafe and SLM were used in roughly equal amounts.

Yeah, I used SLM in the old days. Given how devoted Microsoft is to eating your own dog food, the fact that there are still groups that don’t use SourceSafe says something about how bad that product must be.