Editing Advanced Systems Format (section)

==License==
The specification is downloadable from the Microsoft website,<ref>{{Cite web|url=http://download.microsoft.com/download/7/9/0/790fecaa-f64a-4a5e-a430-0bccdab3f1b4/ASF_Specification.doc|title=ASF Specification Download}}</ref> and the format can be implemented under a [[license]] from Microsoft that however does not allow distribution of sources and is not compatible with [[Open-source software|open source]] licenses. The author of the free software project [[VirtualDub]] reported that a Microsoft employee informed him that his software violated a Microsoft patent regarding ASF playback.<ref name="adv">{{citation |url=http://www.advogato.org/article/101.html |title=Advogato: Microsoft patents ASF media file format, stops reverse engineering |archive-url=https://web.archive.org/web/20170628194627/http://www.advogato.org/article/101.html |archive-date=2017-06-28 |access-date=2019-03-11 |url-status=dead }}</ref>

Certain [[Error detection and correction|error-correcting]] techniques related to ASF were patented in the United States ([https://patents.google.com/patent/US6041345A/ United States Patent 6,041,345] Levi, et al. March 21, 2000) by Microsoft until August 10, 2019.