2026
October, 2026
- October 5
- Uploaded SkyKakapo 157.0 TEST4. Changes from 157.0 TEST3: Enabled browser sandboxing during PGO training.
- October 4
- Uploaded SkyKakapo 157.0 TEST3. Changes from 157.0 TEST2: Disabled the Machine Outliner and TeInliner.
September, 2026
- September 28
- Uploaded SkyKakapo 157.0.
- Uploaded SkyKakapo 157.0 TEST1. Changes from 157.0: Increased the Machine Outliner rerun count from 0 to 1.
- Uploaded SkyKakapo 157.0 TEST2. Changes from 157.0 TEST1: Enabled Partial Inlining.
- September 22
- Uploaded SkyKakapo 156.0.1.
- September 19
- Uploaded
SkyKakapo 156.0 TEST4. Changes from 156.0 TEST3:
- Applied conservative PGO Machine Outlining and isolated the generated cold functions in a dedicated subsection.
- Uploaded
SkyKakapo 156.0 TEST3. Changes from 156.0 TEST2:
- Attempt to mitigate an issue in the DLL blocklist that could cause a crash.
- When the MOZ_CRASHREPORTER environment variable is set, create a crash dump without submitting a crash report.
- Uploaded
SkyKakapo 156.0 TEST4. Changes from 156.0 TEST3:
- September 16
- Uploaded SkyKakapo 156.0 TEST2. Changes from 156.0 and 156.0 TEST1: Machine Outlining has been disabled to investigate intermittent tab crashes.
- September 15
- Uploaded SkyKakapo 156.0 TEST1. Changes from 156.0: Low-frequency functions generated by Machine Outlining are isolated in a dedicated subsection.
- Uploaded SkyKakapo 156.0. Reduced the binary size while keeping performance impact low by adopting the approach tested in 155.0.1 TEST3.
- September 14
- Uploaded SkyKakapo 155.0.1 TEST4. Changes from TEST3: Code executed during PGO training is now excluded from Machine Outlining.
- September 13
- Uploaded SkyKakapo 155.0.1 TEST3. Changes from TEST2: LLVM 22.1.8 was customized to allow linking with the -mllvm:-enable-machine-outliner=conservative-pgo linker option. The resulting binaries are smaller, while stability and performance are still under verification.
- September 12
- Uploaded SkyKakapo 155.0.1 TEST2. Changes from TEST1: Build toolchain updated to LLVM 22.1.8, Rust 1.98.1, and Visual Studio 2026.
- September 8
- A SourceForge project page for SkyKakapo Browser has been created. Distribution will eventually be handled exclusively through SourceForge.
- September 6
- Uploaded SkyKakapo 155.0.1 TEST1. To strengthen privacy protection, reduced differences from Firefox that can be detected externally.
- September 4
- Uploaded SkyKakapo 155.0.1.
- September 3
- Uploaded SkyKakapo 155.0 TEST1. Fixed an issue where browser icon customization could be disabled under certain conditions, causing the browser icon card to disappear from Settings (Bug 2068288). Also added a button to re-enable the customization feature when it has been disabled.
- September 1
- Uploaded SkyKakapo 155.0.
August, 2026
- August 26
- Uploaded SkyKakapo 154.0.1 TEST1. Party Parrot has been added as a browser icon customization option. Your chosen browser icon is now also reflected in the tab icons for about:newtab, about:home, and about:welcome. Your tabs might be a little happier now. 🦜
- August 25
- Uploaded SkyKakapo 154.0.1.
- August 23
- Uploaded SkyKakapo 154.0 TEST3. Changes from TEST2: Added support for disabling all shortcut file creation in the Start menu by setting the environment variable TT_DISABLE_START_MENU_SHORTCUT_CREATION=1 (maybe).
- August 22
- Uploaded SkyKakapo 154.0 TEST2. Added support for disabling normal browsing shortcut creation with the TT_DISABLE_NORMAL_BROWSING_SHORTCUT_CREATION=1 environment variable.
- August 21
- Uploaded SkyKakapo 154.0 TEST1. During profile import, profiles are less likely to fail to import when long-path data exists in certain subfolders.
- August 18
- Uploaded SkyKakapo 154.0.
- Added an explanation of import failures caused by long paths to the SkyKakapo FAQ.
- Firefox Private Builds were discontinued with the 153 series. For information on migrating to SkyKakapo, please see Migrating from Firefox Private Builds to SkyKakapo.
- August 16
- Uploaded SkyKakapo 153.0.4 Preview 2. The number of locales supported by custom UI has been expanded to 22. Supported locales: en-US, ja, zh-TW, zh-CN, de, fr, nl, bg, vi, ko, es-ES, pt-BR, pt-PT, ru, it, pl, ar, lv, tr, fi, hu, uk. Note that es-AR, es-CL, and es-MX fall back to es-ES.
- August 12
- Uploaded SkyKakapo 153.0.4 Preview 1. Fixed an issue where inflected brand names were not replaced correctly.
- August 11
- Uploaded Firefox 153.0.4 x64 SSE3 private build.
- August 8
- Uploaded
SkyKakapo 153.0.3 Preview 3. The following prefs have been set to false and locked.
- nimbus.telemetry.targetingContextEnabled
- browser.aboutwelcome.experimentsGate.enabled
A description of Firefox Private Build Profile Folder Locations was written.
- August 6
- Uploaded SkyKakapo 153.0.3 Preview 2. Mitigated an issue where the custom UI failed to reflect browser language changes.
- Added the SkyKakapo gallery, including brief descriptions of its unique features.
- August 4
- Uploaded SkyKakapo 153.0.3 Preview 1.
- Uploaded Firefox 153.0.3 x64 SSE3 private build.
July, 2026
- July 29
- Updated the tmemutil.ini documentation.
- Uploaded SkyKakapo 153.0.1 Preview 1. Added support for disabling Private Browsing shortcut creation with the TT_DISABLE_PRIVATE_BROWSING_SHORTCUT_CREATION=1 environment variable.
- July 28
- Uploaded Firefox 153.0.1 x64 SSE3 private build. Added support for disabling Private Browsing shortcut creation with the TT_DISABLE_PRIVATE_BROWSING_SHORTCUT_CREATION=1 environment variable.
- July 21
- Uploaded SkyKakapo 153.0 Preview 1. Added a profile import feature to the File menu.
- July 20
- Uploaded Firefox 153.0 x64 SSE3 private build.
- July 15
- Uploaded Firefox 152.0.6 x64 SSE3 private build.
- July 10
- Uploaded SkyKakapo 152.0.5 TEST1.
- July 8
- Uploaded Firefox 152.0.5 x64 SSE3 private build.
- July 1, 2026
- Uploaded Firefox 152.0.4 x64 SSE3 private build.
June, 2026
- June 26
- Uploaded Firefox 152.0.3 x64 SSE3 private build.
- June 23
- Uploaded Firefox 152.0.2 x64 SSE3 private build.
- June 19
- Uploaded Firefox 152.0.1 x64 SSE3 private build.
- June 15
- Uploaded Firefox 152.0 x64 SSE3 private build.
- June 9
- Uploaded Firefox 151.0.4 x64 SSE3 private build.
- June 2
- Uploaded Firefox 151.0.3 x64 SSE3 private build.
May, 2026
- May 26
- Uploaded Firefox 151.0.2 x64 SSE3 private build.
- May 21
- Uploaded Firefox 151.0.1 x64 SSE3 private build.
- May 19
- Uploaded Firefox 151.0 x64 SSE3 private build.
- May 12
- Uploaded Firefox 150.0.3 x64 SSE3 private build.
- May 8
- Uploaded Firefox 150.0.2 x64 SSE3 private build.
April, 2026
- April 28
- Uploaded Firefox 150.0.1 x64 SSE3 private build.
- April 20
- Uploaded Firefox 150.0 x64 SSE3 private build.
- April 6
- Uploaded Firefox 149.0.2 x64 SSE3 private build.
March, 2026
- March 24
- Uploaded Firefox 149.0 x64 SSE3 private build.
- March 11
- Uploaded Firefox 148.0.2 x64 SSE3 private build.
February, 2026
- February 25
- Updated Firefox 148.0 x64 SSE3 private build. Fixed a bug that caused crashes on some websites, including hCaptcha.
- February 24
- Uploaded Firefox 148.0 x64 SSE3 private build.
- February 16
- Uploaded Firefox 147.0.4 x64 SSE3 private build.
- February 11
- Uploaded
Firefox 147.0.3 x64 SSE3 private build TEST2. Changes from TEST1: Added the following linker options.
- -mllvm:-pgo-memop-count-threshold=5000
- -mllvm:-pgo-memop-percent-threshold=98
- -mllvm:-pgo-memop-max-version=1
- -mllvm:-pgo-memop-optimize-memcmp-bcmp=false
- February 7
- Uploaded Firefox 147.0.3 x64 SSE3 private build TEST1. Applied devirtualization of virtual calls with a single resolved target and memmove specialization based on value profiling.
- February 4
- Uploaded Firefox 147.0.3 x64 SSE3 private build.
January, 2026
- January 27
- Uploaded Firefox 147.0.2 x64 SSE3 private build.
- January 19
- Uploaded Firefox 147.0.1 x64 SSE3 private build TEST2. Changes from TEST1: Fixed a bug where the order of some high-priority data was unexpectedly rearranged.
- January 18
- Uploaded Firefox 147.0.1 x64 SSE3 private build TEST1. Isolated a subset of infrequently accessed data into a dedicated area, aiming to improve the locality of higher-priority data and reduce CPU cache misses.
- January 17
- Uploaded Firefox 147.0.1 x64 SSE3 private build.
- January 14
- Uploaded Firefox 147.0 x64 SSE3 private build TEST3. Deferred the approach to reordering internal data in the program.
- January 9
- Uploaded Firefox 146.0.1 x64 SSE3 private build TEST3. Changes from TEST2: Applied LLVM's CDSort (Cache-Directed Sort) approach to the layout of a subset of internal global data (maybe).