title: Swiftweasel
text: # Swiftweasel
  
  Swiftweasel was a fork of Mozilla Firefox available for the Linux platform only.
  
  ## Optimization
  
  Swiftweasel is optimized using the following methods:
  
  ### P.G.O.
  
  As of the 3.0.3 release, Swiftweasel has shifted its primary optimization from processor specific to profile-guided optimization (PGO). It is a two step building process. The application is compiled one time and then run to produce a profile. The profile is then used to guide a second compilation of the application. Some of the older optimizations are still used, but there are now only Intel and AMD versions of each build. It is released compiled in a tar.gz package. There are also separate installers for Ubuntu and Arch linux available through their communities.
  
  ### Binary code optimization
  
  * Swiftweasel is compiled with options that optimize for speed rather than binary size.
     * Compiled with the -O3 compile flag (the highest level), with the resulting Swiftweasel binary being larger than that of Firefox.
     * Firefox is compiled with the -Os compile flag, which is for binary size.
  * Binaries incorporate additional instruction sets:
     * Intel and AMD: SSE, SSE2, SSE3, and MMX.
     * AMD only: 3DNow!
  * Optimization specific to the build microprocessor architecture.
     * Intel 32bit: Pentium 4 (Prescott), Pentium 4, Pentium M, Pentium III, Pentium II;
     * Intel 64bit: Nocona;
     * AMD: Athlon XP, Athlon, K6-2, Athlon;
     * AMD64: Athlon64, Opteron.
  * Compiled with newer versions of GCC (Firefox 2.0 uses 3.3.2, Swiftweasel 2.0 uses 4.0.3, and Swiftweasel 3.0.3 uses 4.2.3).
  
  Increased Security
  
  * Better protection from Buffer overflow attacks (Swiftweasel 2.0 uses -D_FORTIFY_SOURCE=2; Firefox 2.0 uses gcc 3.x, which does not support this).
  
  Simplify
  
  * IPv6 DNS lookups are disabled, preventing slowdowns;
  * HTTP pipelining is enabled by default. Note that Fasterfox provides a GUI to adjust these settings.
  * For full details, users can download source packages with all changes listed.
  
  ## Installed extensions
  
  Swiftweasel has several extensions installed by default.
  
  * XForms
  * AdBlock Plus
  * User Agent Switcher
  * Quick Locale Switcher
  
  ## Swiftweasel-specific changes
  
  Changes made to Swiftweasel include:
  
  * The default icon set has been replaced with the Kempelton icon set.
  * Swiftweasel uses its own settings directory. The settings, including bookmarks, history, and extensions are imported from Mozilla Firefox the first time Swiftweasel runs.
  * Plugins stored in /lib/mozilla/plugins and /lib/Firefox/plugins are detected and used by Swiftweasel.
  
  ## Swiftdove
  
  The Swiftweasel project also builds optimized 32 and 64bit builds of the Thunderbird email client known as Swiftdove.
  
  ### Optimizations
  
  As of the current version 2.0.0.21, Swiftdove is also PGO optimized.
  
  ### Plugins
  
  The 2.0.0.21 builds of Swiftdove include the 0.9 Lightning calendar plugin installed by default.
  
  