The L4 µ-Kernel Family




L3, a predecessor of L4/x86

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Welcome to the L4 webpages!

This site contains information on the L4 µ-kernel API and the various implementations of this API. It also contains some legacy information about the L3 µ-kernel and operating system.

If you are new to this site, please start exploring it at the overview page.

What's new

June 2010
L4Re and Fiasco.OC available
A generation of L4 based software is available with L4Re and Fiasco.OC.

Novemer 2007
Wiki available
A wiki is now available at, open to everyone (after registration).

March 2007
TUD:OS/DROPS available via SVN
The repository has been migrated to SVN.

19 Oct 2005
L4.Sec Reference Manual available
The first draft of the L4.Sec Microkernel Reference Manual has been made available. Please refer to the L4.Sec site.

26 Sep 2005
Fiasco 1.2 released
A new version of the Fiasco Microkernel has been released. Further information can be found on the Fiasco site.

01 Sep 2004
L4Env 0.2 released
An update to L4Env, DDE and libstdc++ have been make available.

19 Aug 2004
L4Linux-2.6 released
An L4Linux version based on Linux 2.6 has been released. It is based on L4Env and available for x86 systems. It also runs on Fiasco-UX.

11 Nov 2003
Fiasco 1.1 released
Fiasco 1.1 is a mainly a bugfix release with a few feature enhancements.

30 Jun 2003
L4Env and DDE 0.1 released
The DROPS team has released version 0.1 of L4Env, the L4 Environment, and DDE, the Device Driver Environment. L4Env is a programming environment for application development on top of the L4 microkernel family. DDE is an environment for Linux device drivers for using native Linux 2.4 drivers together with L4Env.

2 May 2003
Pistachio 0.1 released. Support for Hazelnut, L4/MIPS, and L4/Alpha discontinued
The L4KA team has released version 0.1 of the Pistachio microkernel. It is the first available implementation of the experimental L4 Version X.2 kernel API, which will eventually evolve into L4 version 4 and is fully 32- and 64-bit clean and provides multiprocessor support. Pistachio is available for the following hardware architectures: x86, IA64, PowerPC, Alpha, and 64-bit MIPS.

In related news, the UNSW DiSy group has announced that they are discontinuing all development on the L4/Alpha and L4/MIPS kernels. They now use Pistachio exclusively for new work. Also, L4KA has discontinued support for their Hazelnut kernel to concentrate on Pistachio development.

2 Apr 2003
Fiasco 1.0 released
TU Dresden has released Fiasco 1.0 for x86 PCs and for L4 emulation under Linux/x86. The Fiasco microkernel is a complete implementation of the L4 version 2 interface. More information is available from the README file accompanying the release.

28 Jan 2002
The L4KA team has released a new experimental L4 specification, version X.2. This specification signifies a big step towards the upcoming ``stable'' specification, version 4.

13 Dec 2001
Added a new L4 implementation to the implementations page: L4/S*, an implementation for the Siroyan OneDSP.

19 Nov 2001
The proceedings of the Second Workshop on Microkernel-based Systems are online. Workshop papers interesting to L4 developers have been added to the L4 Developer's Bibliography.

23 Jul 2001
Added an L4 developer's bibliography to this website.

10 Jun 2001
In Memoriam Jochen Liedtke

Prof. Dr. Jochen Liedtke, chair of the System Architecture Group at the University of Karlsruhe, passed away unexpectedly on Sunday, June 10th. Jochen was the main visionary behind the L4 microkernel interface. The L4 community loses an excellent teacher, mentor, colleague, and friend.

15 Sep 2000
L4KA is out! A team at the University of Karlsruhe has released a new implementation of the L4 interface for x86 and StrongARM. Congratulations to the L4KA team!

2 Aug 2000
Frank Mehnert has implemented the RT-Linux API on top of L4 and has compared the real-time characteristics of Fiasco, L4/x86, and RT-Linux.

28 September 1999
Released a new package called oskit10_support which adapts the current OSKit 0.97 to Fiasco and L4. With this library, many OSKit applications can run unchanged on top of Fiasco and L4. This package is part of the l4 module - download it via remote CVS!

8 June 1999
Read-only remote CVS is now available for the L4/x86 development environment, along with some other components of the DROPS system!

24 May 1999
Redesigned this webpage.

Last modified: Sun Feb 08 2015, 10.49:19 CET

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