Fraunhofer l3enc was the first MP3 (back then called MPEG audio layer 3, that's why l3enc) software encoder. The official 1.0 version was released on 1994-07-13, and before that only very expensive hardware encoders existed (not that l3enc was not expensive itself, registration for version 2.0 cost 350DM - ~U$250)

Also, it was truly multiplatform: It ran on MS DOS (x86), Linux (x86), Solaris (SPARC), SunOS (SPARC), Irix (MIPS), and NeXT (68K/x86/SPARC/HPPA). The first (pre-1.0) DOS versions even featured fixed point math encoder and decoder for the 8088 architecture.

FhG distributed with l3enc an MPEG layer 3 FAQ and a small collection of test bitstreams (1.370kB).

By the end of 1997 l3enc stopped being developed in favour of the development of MP3enc. The l3enc webpage can still be seen at the Internet Archive, here.


••••• The First Ever Publicly Available MP3 Software Encoder •••••
Date: 1994-03-16
Version: 0.99a
Interface: Command line
Platform: DOS
Download: l3enc099a.zip - 311kB

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Date: 1997-12-05
Version: 2.72
Interface: Command line (also Windows fronted)
Platform: DOS
Download: l3enc272.zip - 564kB

Platform: Linux x86
Download: l3enc272.linux.tar.gz - 206kB

Platform: NeXTstep
Download: l3enc272.next.tar.gz - 749kB

Platform: SGI Irix
Download: l3enc272.sgi.tar.gz - 359kB

Platform: Solaris SPARC
Download: l3enc272.solaris.tar.gz - 236kB

Platform: SunOS
Download: l3enc272.sun4.tar.gz - 284kB

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Date: 1997-08-27
Version: 2.71
Interface: Command line
Platform: DOS
Download: l3enc271.zip - 295kB

Platform: Solaris
Download: l3enc271.solaris.tar.gz - 236kB

Platform: Linux
Download: l3enc271.linux.tar.gz - 205kB

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Date: 1997-06-30
Version: 2.70
Interface: Command line
Platform: DOS
Download: l3enc270.zip - 319kB

Platform: SGI Irix
Download: l3enc270.sgi.tar.gz - 275kB

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Date: 1996-11-07
Version: 2.61
Interface: Command line
Platform: DOS
Download: l3enc261.zip - 301kB

Platform: Linux x86
Download: l3enc261.linux.tar.gz - 198kB

Platform: NeXTstep
Download: l3enc261.next.tar.gz - 726kB

Platform: SGI Irix
Download: l3enc261.sgi.tar.gz - 271kB

Platform: SunOS
Download: l3enc261.sun4.tar.gz - 285kB

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Date: 1996-07-31
Version: 2.60
Interface: Command line
Platform: DOS
Download: l3enc260.zip - 312kB

Platform: Linux
Download: l3enc260.linux.tar.gz - 198kB

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Date: 1995-09-04
Version: 2.00
Interface: Command line
Platform: DOS
Download: l3enc200.zip - 287kB

Platform: NeXTstep
Download: l3enc200.next.tar.gz - 686kB

Platform: Linux x86
Download: l3enc200.linux.tar.gz - 179kB

Platform: SunOS
Download: l3enc200.sun4.tar.gz - 255kB

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Date: 1995-02-22
Version: 1.50
Interface: Command line
Platform: DOS
Download: l3enc150.zip - 240kB

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Date: 1994-07-13
Version: 1.00
Interface: Command line
Platform: DOS
Download: l3enc100.zip - 126kB

Platform: SunOS
Download: l3enc100.sun4.tar.z - 394kB

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Date: 1994-06-13
Version: 0.99c
Interface: Command line
Platform: DOS
Download: l3enc099c.zip - 312kB

Platform: SunOS
Download: l3enc099c.sun4.tar.z - 284kB