hApple's San Francisco "free" font download is a work of art. Not because of the quality of the typography but because of the intellectual property engineering they've devised, comparable to the pyramids of Gizah to make it impossible to use in systems other than Apple's. Curiously, I may be able to reverse engineer it under the law of the jurisdiction where I live.
Jonkman Microblog is a social network, courtesy of SOBAC Microcomputer Services. It runs on GNU social, version 1.2.0-beta5, available under the GNU Affero General Public License.
All Jonkman Microblog content and data are available under the Creative Commons Attribution 3.0 license.