The Composite Component-Based OS

This is the source code for the Composite component-based OS. Even low-level system policies such as scheduling, memory mapping, and synchronization are defined as discrete user-level components. Each component exports an interface used to harness its functionality, and components are composed together to form an executable system.

Please see for publications and more information.


  • master is the original system with a full user-level set of components.
  • ppos is the Speck kernel emphasizing scalable predictability.
  • tcaps has mainly been integrated into ppos, but a few unrelated pieces remain.

Research features of Composite

See a summary of the research directions of Composite at

Where to start – a tour of the source code

  • Please read the doc/ directory for more information on how the code is organized

  • Join the [email protected] mailing list

  • To run Composite, you start by reading the installation and usage summary in docs/

Composite system support

  • x86-32
  • booting using Linux 2.6.33 or 2.6.36 (see Hijack support for booting information)
  • networking using Linux drivers and a modified tun/tap driver to communicate with Composite

Important note

The code is pre-alpha quality. Some parts are quite solid, many others are absolutely not. Please consult with us to determine if it is right for your use-case.


This code is licensed under the GPL version 2.0 with the classpath exception:

The Composite Component-Based OS
Copyright (C) 2009 Gabriel Parmer

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

Linking this library statically or dynamically with other 
modules is making a combined work based on this library. Thus, 
the terms and conditions of the GNU General Public License 
cover the whole combination.

As a special exception, the copyright holders of this library 
give you permission to link this library with independent modules 
to produce an executable, regardless of the license terms of 
these independent modules, and to copy and distribute the resulting 
executable under terms of your choice, provided that you also meet, 
for each linked independent module, the terms and conditions of 
the license of that module. An independent module is a module which 
is not derived from or based on this library. If you modify this 
library, you may extend this exception to your version of the 
library, but you are not obligated to do so. If you do not wish to 
do so, delete this exception statement from your version.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

This license is not set in stone, and we would be willing to negotiate on a case-by-case basis for more business-friendly terms. The license should not prevent you from using this OS, as alternatives can be arranged. It should prevent you from stealing the work and claiming it as your own.


We’d like to sincerely thank our sponsors. The Composite Component-Based OS development effort has been supported by grants from the National Science Foundation (NSF) under awards CNS 1137973, CNS 1149675, and CNS 1117243.

Related Repositories



a composite render engine for universal (isomorphic) express apps to render both plain react views and react-router views ...



Meteor.publishComposite provides a flexible way to publish a set of related documents from various collections using a reactive join ...



Jitsi Videobridge is an XMPP server component that allows for multiuser video communication. Unlike the expensive dedicated hardware videobridges, Jitsi Videobridge does not mix the video channels into a composite video stream, but only relays the receive ...



Orckestra CMS Foundation - .NET based, open source and a bundle of joy! (Formerly known as Composite C1) ...

Top Contributors

gparmer gedare interwq songjiguo georgit rezie2 ryuxin jkaivo chrismanderson asweeney86 Neymello knowlt15