launchd existed — albeit was decided against in large part down to licensing concerns (it was, at the time, only available under the Apple Public Source License

launchd existed — albeit was decided against in large part down to licensing concerns (it was, at the time, only available under the Apple Public Source License 2.0 (APSL)), though a couple of months later it was re-licensed under the Apache License 2.0 to alleviate such concerns. OpenSolaris's SMF was considered too. AIUI both were purely decided against on licensing grounds, although they met the technical requirements. Had launchd already been available under the Apache License 2.0 at the time, who knows, it might now be well-established on Linux. (AIUI, GPL compatibility is not an issue here — the problem is more the APSL isn't compatible with, e.g., the Debian Free Software Guidelines (DFSG) and hence would never be adopted by the Linux community at large.)