Software Licensing Basics

• The difference between a "viral" copyleft license (GPL) when compared to closed-source-friendly Apache, and non-viral MS-PL/MS-RL.

• When you should use LGPL, and when not to.

• License compatibility. For example, you may link a modern Apache license'd library to a GPLv3 code, but not GPL 1 or 2.

• If you own the source code in it's entirety, you may publish it under as many (or few) licenses as you wish.

Note to S.O. community:
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