The OpenWrt project started in January 2004. The first OpenWrt versions were based on Linksys GPL sources for WRT54G and a buildroot from the uclibc project. This version was known as OpenWrt "stable release" and was widely in use. There are still many OpenWrt applications, like the Freifunk-Firmware or Sip@Home, which are based on this version.
In the beginning of 2005 some new developers joined the team. After some months of closed development the team decided to publish the first "experimental" versions of OpenWrt. The experimental versions use a heavily customized build system based on buildroot2 from the uclibc project. OpenWrt uses official GNU/Linux kernel sources and only adds patches for the system on chip and drivers for the network interfaces. The developer team tries to re-implement most of the proprietary code inside the GPL tarballs of the different vendors. There are free tools for writing new firmware images directly into the flash (mtd), for configuring the wireless lan chip (wlcompat/wificonf) and to program the VLAN-capable switch via the proc filesystem.
The codename of the first OpenWrt release is "White Russian". 1) The development of the White Russian line has ended with the release of OpenWrt 0.9. Subsequent releases continue the version scheme without the '.0' prefix, and with the version number derived roughly from the year in which the release falls. Consequently, OpenWrt 7 and 8, both in the "Kamikaze" stream, were released throughout 2007-2008. In 2010 OpenWrt 10 was ready, in a new release line codenamed "Backfire". The current newest stable release is OpenWrt 14 "Barrier Breaker". The development of the next release, "Chaos Calmer", is taking place in the GIT or subversion (SVN) repository.
Stable release version numbers are made from the year and the month when a new stable branch was created. An additional third number indicates a service or interim release from that branch.
Pre-built images and the source code of the latest stable release are available on an extra page.
The legacy White Russian releases are still available, but are neither supported nor maintained. The latest White Russian release has version 0.9, released in 2007.
Substantial improvements to the build environment were made under the Buildroot-NG fork in August and September 2006, and these were merged back into the main Kamikaze development branch in mid-October 2006 and became the first official Kamikaze release. There were several Kamikaze releases in 2007-2010.
The first Backfire release, OpenWrt 10.03, was released in April 2010. A maintenance release (Backfire 10.03.1) was released in December 2011.
The first Attitude Adjustment release, OpenWrt 12.09, was released in April 2013.
Attitude Adjustment is the version recommended for devices with 4mb of flash. To build a version to which important security updates have been added, download a later version than the original final release, for instance:
svn co -r 39407 svn://svn.openwrt.org/openwrt/branches/attitude_adjustment aa_r39407
Release preparations began with branching Barrier Breaker in July 2014 (r41864). It was released on October 2nd, 2014.
Developers have voiced the intention of releasing Chaos Calmer (CC) before the end of the year (2014)*. The CC release will use 3.18 LTS kernel as baseline.
*There was a delay, but on May 20, 2015, Chaos Calmer reached the Release Candidate 1 stage.
The bleeding edge development trunk, where the main development is being made, is called as "trunk" in the SVN repository.
Until February 2011 it was confusingly also called "Kamikaze" (like an earlier stable branch), but with r25514 it was renamed to "Attitude Adjustment". Since then it has been renamed after each release branching to match the next release. In July 2014 it was renamed to "Chaos Calmer" with r41870 and r41871
The name of the currently installed version is displayed in the console
The following is a complete history of post White Russian releases:
|Testing - trunk snapshots||continuously||Chaos Calmer|
|Barrier Breaker 14.07||2014 October||Barrier Breaker||r42625|
|Attitude Adjustment 12.09||2013 April||Attitude Adjustment||r36088|
|Backfire 10.03.1||2011 December||Backfire||r29592|
|Backfire 10.03||2010 April||Backfire||r20728|
|Kamikaze 8.09.2||2010 January||Kamikaze||r18801|
|Kamikaze 8.09.1||2009 June||Kamikaze||r16278|
|Kamikaze 8.09||2008 September||Kamikaze||r14510|
|Kamikaze 7.09||2007 September||Kamikaze||r7831|
|Kamikaze 7.07||2007 July||Kamikaze|
|Kamikaze 7.06||2007 June||Kamikaze||r7204|
|White Russian 0.9||2007 January||White Russian||r6257|