The Boost license permits the creation of derivative works for commercial or -non-commercial use with no legal requirement to release your source code. Other -differences include Boost not requiring reproduction of copyright messages for -object code redistribution. The GPL is also much longer.
+The Boost license permits the creation of derivative works for +commercial or non-commercial use with no legal requirement to release +your source code. Other differences include Boost not requiring +reproduction of copyright messages for object code redistribution, and +the fact that the Boost license is not "viral": if you +distribute your own code along with some Boost code, the Boost license +applies only to the Boost code (and modified versions thereof); you +are free to license your own code under any terms you like. The GPL is +also much longer, and thus may be harder to understand.
Why the phrase "machine-executable object code generated by a source language processor"?