Fraunhofer l3enc the first publicly available software, the PCM files (. Wav) was able to encode into MP3 format. It was first released in July 1994. It was available as a command-line tool for MS- DOS, Linux, Solaris, SunOS, NeXTSTEP, and IRIX. It was distributed as shareware and was limited to 112 kbit / s. A license for unlimited use (use of bit rates up to 320 kbit / s ) cost 350 German marks.

Since the publication (9 September 1995) by Fraunhofer WinPlay3, the first real-time MP3 playback software, it was possible MP3 files to store on personal computers and play. For full playback quality (stereo) would have as a minimum requirement requires a 486DX2/66-Prozessor.

End of 1997, the development of l3enc favor of mp3enc has been set, which is the successor of l3enc. He was often referred to as the "MP3 encoder with the best quality ." He was available for Microsoft Windows, Linux, Solaris, SunOS, IRIX and Alpha. The development of mp3enc heard late in 1998 in favor of a parallel branch on, the FhG had developed for some time and was called the Fastenc. All of these programs are no longer actively marketed. At the Fraunhofer site now a MP3 Surround encoder and a MP3HD codec and software tools are applied.