What topics can I ask about here?
Unix and Linux Stack Exchange is for users of Linux, FreeBSD and other Un*x-like operating systems.
If your question is about:
- Using or administering a *nix desktop or server
- The Unix foundation underlying OS X (but generally not frontend application questions)
- The underlying *nix OS on an embedded system or handheld device (e.g. an Android phone)
- Shell scripting
- Applications packaged in *nix distributions (note: being cross-platform does not disqualify)
- UNIX C API and System Interfaces ( within reason )
then you're in the right place. Note that Ubuntu posts are a special case. If your question applies to Ubuntu only, or you're looking for answers that are Ubuntu-specific, you should post it on the Ask Ubuntu Stack Exchange site. If your question applies to other distros or you welcome more generic solutions, you're in the right place here.
If your question is a programming question, requiring knowledge of programming languages other than unix shell scripting languages, ask on Stack Overflow.
Please note that requests for learning materials (tutorials, how-tos etc.) are off topic. The only exception is questions about where to find official documentation (e.g. POSIX specifications).
For more help, see "What types of questions should I avoid asking?"
Cross-posting is strongly discouraged -- if you post on one site and then change your mind it can always be migrated to another. If you're not sure if your question is on-topic, ask on meta or just give it a try and the community will decide.
If your question is not specifically on-topic for Unix and Linux Stack Exchange, it may be on topic for another Stack Exchange site. If no site currently exists that will accept your question, you may commit to or propose a new site at Area51, the place where new Stack Exchange communities are democratically created.