Various Sagebrush programs are able to record and play MP3, but only if you already have an ACM MP3 audio codec installed on your computer, which was common during Windows XP but less likely in later versions of Windows. We do not bundle an MP3 encoder with our products because the technology is covered by software patents, whose validity is recognized in the country where Sagebrush is located. The licensing fees are prohibitive.
When do the patents covering MP3 encoding and decoding actually expire in the USA? That is complicated, as issues relating to software patents tend to be. Tunequest provides a handy list of patents, with the last expiring December 30, 2017. The Wikipedia article on MP3 raises the question of validity of the later patents:
The various MP3-related patents expire on dates ranging from 2007 to 2017 in the U.S. The initial near-complete MPEG-1 standard (parts 1, 2 and 3) was publicly available on December 6, 1991 as ISO CD 11172. In the United States, patents cannot claim inventions that were already publicly disclosed more than a year prior to the filing date, but for patents filed prior to June 8, 1995, submarine patents made it possible to extend the effective lifetime of a patent through application extensions. Patents filed for anything disclosed in ISO CD 11172 a year or more after its publication are questionable; if only the known MP3 patents filed by December 1992 are considered, then MP3 decoding may be patent free in the US by September 2015 when U.S. Patent 5,812,672 expires which had a PCT filing in Oct 1992.
Just for the sake of caution, let us take the more conservative date of December 30, 2017.
(We are not lawyers, and nothing in this article should be taken as legal advice.)
We hope and expect to be supporting RecAll and RecAll-PRO well into the next decade, so it is quite possible to wait out this particular portfolio of patents.