This question is coming back often, and the general answers are very often the same. In an objective to concentrate useful information in one place, here is a community wiki about it.
How can I convert this filetype to pdf?
This question will have two kind of answers:
- The generic case, which works for most filetypes.
- The specific cases, which should be one answer per filetype.
As it is community wiki, feel free to edit this question to improve it as well.