Software

x64 SSE3

Reduced the binary size while keeping performance impact low by adopting the approach tested in 155.0.1 TEST3.

SkyKakapo 156.0 [2026091423 en-US win64 sse3 cspgo] (96.2MB)

• SHA256: 19e333ec1d9b8363558862e86593a67a367b130c31c4b976ab11442d8063755a
• SHA1: b42e222957fca5e5f5dad076162e166dd6eafeb3
• MD5: 6ffee0170370c4c088bab04f3e9484c7

x64 SSE3

Changes from 156.0: Low-frequency functions generated by Machine Outlining are isolated in a dedicated subsection.

SkyKakapo 156.0 TEST1 [2026091502 en-US win64 sse3 cspgo] (95.8MB)

• SHA256: b3a7141d1a774280d4863c8f759ade7b9a6aadf25c2699aae91a1f78de699aa3
• SHA1: 5456c8ea08d8994bf2d90b420ed4dca8f136d749
• MD5: b95b958c41ee4e9f2b69b54bfa104e47

x64 SSE3

Changes from 156.0 and 156.0 TEST1: Machine Outlining has been disabled to investigate intermittent tab crashes.

SkyKakapo 156.0 TEST2 [2026091609 en-US win64 sse3 cspgo] (92.1MB)

• SHA256: 301a27ccf1060e1c0abb5572be87de7350f67416fa4a5eff3121a975a1d20db3
• SHA1: cc621c9bd34e0c282c98d451e1f762dd41acd92c
• MD5: 3a1515e188a81d2fc38541af89bcdc64

x64 SSE3

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.

SkyKakapo 156.0 TEST3 [2026091900 en-US win64 sse3 cspgo] (93.7MB)

• SHA256: 57baa1da08dd1daf7690b8208b881b6acc780af492052c922f99138d23eea8d9
• SHA1: 138af16926fea492e80796f03d659590cc0d5568
• MD5: 770f284c7c39a7c783ece2278c9cc624

x64 SSE3

Changes from 156.0 TEST3: Applied conservative PGO Machine Outlining and isolated the generated cold functions in a dedicated subsection.

SkyKakapo 156.0 TEST4 [2026091901 en-US win64 sse3 cspgo] (96.8MB)

• SHA256: e8f7b171ec850a9a9b81efe0aecae3eeda5fed67632b3779a6906f31455f0284
• SHA1: ed44c9198cef0362a3b26baaba7ff11367c7bd4c
• MD5: dfb6a69ce14b37dc394b1183b12fd610

I have been publishing builds based on Firefox source code with my own modifications as Firefox Private Builds since Firefox was first released.

However, according to the Mozilla Trademark Guidelines, independent projects that use Mozilla's open source code are required to use their own branding.

Therefore, I will discontinue publishing Firefox Private Builds and publish SkyKakapo, a browser with its own branding, as the successor to Firefox Private Builds.

By default, Firefox Private Builds and SkyKakapo use different locations for storing profile folders. Therefore, a profile used with Firefox Private Builds cannot be used directly with SkyKakapo in the usual way.

Using SkyKakapo's profile import feature, you can copy an existing profile folder to SkyKakapo's profile folder location and register it as a SkyKakapo profile. The next section explains Firefox Private Build Profile Folder Locations.

I apologize for any inconvenience caused by the migration process, and I appreciate your understanding.

Default:

If you are using the same profile folder as the official Firefox, individual profile folders are stored in the following folder.

%APPDATA%\Mozilla\Firefox\Profiles

When using portable mode:

If Portable=1 is specified in the [General] section of the tmemutil.ini file, individual profile folders are stored in the following folder.

(PortableDataPath)\AppData\Mozilla\Firefox\Profiles

When the profile folder path is specified using the -profile startup switch or the XRE_PROFILE_PATH environment variable:

The specified path is the profile folder path.

To easily find the profile folder of the currently running Firefox Private Build, open "Help" - "More Troubleshooting Information" and check the "Profile Folder" item under "Application Basics".

You can copy an existing profile folder to SkyKakapo's profile folder location and register it as a SkyKakapo profile.

If the menu bar is not displayed, press the Alt key to show it.

Select "Import Profile..." from the File menu and specify the profile folder you want to import. The "Import Profile" dialog will open, allowing you to choose between two profile registration methods: "Classic" and "Profiles menu".

• "Classic" is the classic profile registration method. It may be helpful to think of it as the same type of profile registration used in about:profiles or in the Profile Manager opened with the -p startup switch. See "Profile Manager - Create, remove or switch Firefox profiles".

• "Profiles menu" is a relatively new profile registration method. It registers the profile in the same profile group as the current profile. Only profiles belonging to the same group as the current profile are displayed in the Profiles menu and other new profile management UIs. See "Manage Firefox profiles".

  　

Importing may fail if the full path of a file or folder within the profile is too long. For more information, see the explanation of import failures caused by long paths.

Includes the Menus settings page (about:preferences#menus) in Settings. You can hide unwanted items from some of the major menus.

Those lovely round eyes...

If available storage space becomes low, older versions may be removed without notice.

• Google Drive

Fixed a bug that may cause portabilization to fail.

x64

tmemutil-20231004-x64.7z (58KB)

• MD5: 3c0a9c88329dd1afb4b599f39af2e463
• SHA1: 091077bf3360a8cd085ddfb6ffafaa6be8b5a482
• SHA256: 87acdc00f6b22f90efbc9f0f84063187ee8222fcc953d695672874fef745f974

x64

tmemutil-20130315-x64-test.zip (6KB)

• MD5: 396c86c030bf32a802017be0136a20f5
• SHA1: 30d8579211127c301ef2053567633aebef61d607
• SHA256: 5a19da013c3a6fc733cd330fb27cb49d029c09fa121eb42e323bd905c6306619

If you install SkyKakapo over another build, files from the old and new builds may be mixed together, which can cause problems. In that case, install SkyKakapo in a new folder.

SkyKakapo's profile import feature uses Mozilla's standard I/O functionality to copy profiles. Windows has limitations on the use of long paths, and Firefox's source code does not fully support long paths, so importing a profile containing files or folders with long full paths may fail.

In that case, move the profile folder you want to import to a shorter path and try again. Using a shorter path for SkyKakapo's profile storage location may also improve the situation.

When you open tmemutil.ini and set the value of ProcessAffinityMask to 1 or 2, SkyKakapo uses only a single logical CPU, so the symptom may improve.

Please try the following.

• Try troubleshooting.
• Check whether the same issue can be reproduced with the same version of Firefox.
• Try test DLL.

After trying the above, if you suspect that the issue may be a bug in SkyKakapo, I would appreciate it if you could let me know on the forum or elsewhere. In that case, providing the following information may help narrow down the cause of the problem.

• A description of the problem and how to reproduce it.
• The SkyKakapo version.
• The enabled add-ons (extensions, themes, and plugins).
• The name of the operating system and CPU.

You can specify environment variables. The following are some examples.