For programming languages, there are several examples of commercially run package managers:
- the Java/Kotlin/Scala ecosystem is based around maven central, which is run by Sonatype, Inc.
- Go modules are hosted by Google. Previously, most libraries were hosted on Github
- Rust's crate index is on Github
- The Docker/Moby registry is run by Docker, Inc. (though that might be a stretch for "package manager" :))