7-Zip-fork

A personal fork of 7-Zip by Igor Pavlov, focused on one everyday problem: file names inside zip archives that travel between systems with different languages — a zip made on a Chinese Windows shows garbled names on a Japanese or English one, and vice versa.

Why a fork: the upstream GitHub repository does not appear to take pull requests — at the time of writing none of the PRs opened there had been merged (the maintainer is active in the issue tracker instead). So instead of sending patches upstream, this fork carries them on top of each upstream release.

Upstream: ip7z/7zip · current base: 7-Zip 26.03

What is different from 7-Zip

Reading archives with the wrong names ("receiving side")

• The Extract dialog has a Name code page drop-down: pick 936 (Chinese Simplified) and the names of a legacy zip decode correctly. It always starts at Auto (today's behavior) and is not remembered — a code page fixes one archive.

  

• The File Manager can switch the code page while browsing an archive: View → Name Code Page… reopens a zip or tar in place and keeps your position. It applies only to a plain zip or uncompressed tar backed by one real file; .tar.gz and other multi-handler chains, archives opened directly from a parent archive's memory stream, and paths shortened by the File Manager are disabled. Reopening is currently synchronous, without progress or cancellation; see the detailed DOC.

  

  

• On the command line: 7z l "-mzip.cp=936" archive.zip — the zip. prefix sends the property only to the zip handler, so .7z, .gz and everything else stay untouched. tar.cp works the same way. See DOC/zip-name-encoding.txt for the details and for two PowerShell/terminal pitfalls.

Writing archives that decode everywhere ("sending side")

• The Add to Archive dialog has Use UTF-8 for file names for zip (on by default): names are written as UTF-8 with the UTF-8 flag (bit 11), so any compliant tool decodes them, no guessing involved.

  

Packaging and coexistence

• A small MSI installer that lives next to an official 7-Zip installation: its own product identity, its own folder (7-Zip-fork), and a context menu registered as 7-Zip-fork with its own CLSID — installing or removing it never touches the official 7-Zip.
• A portable set: unzip and run, nothing to install.
• The language files are included, which a build from the upstream sources alone cannot be: they ship only with the official binary release. The interface follows the system language on first run, and Options → Language lists all 90-odd of them. The fork's own strings are translated into Japanese, Simplified and Traditional Chinese; the other languages show them in English.

Install

Take either from the latest Release:

Asset	What it is
7zip-fork-<version>-x64.msi	Installer, coexists with official 7-Zip
7zip-fork-<version>-portable-x64.zip	7zFM.exe, 7zG.exe, 7z.exe, 7zz.exe, 7z.dll, 7-zip.dll, SFX modules, Lang\, docs — run from anywhere
SHA256SUMS.txt	Checksums of both

Version scheme: 26.03-fork.3 is the third fork release on top of 7-Zip 26.03; the MSI carries it as 26.3.3. Release candidates end in -rc.N. Windows x64 only. There is no help file, so the Help buttons do nothing. The OK / Cancel / Apply / Help buttons at the bottom of Options are drawn by Windows and follow the Windows display language, not the language chosen in 7-Zip — upstream is the same. The context menu, on the other hand, picks up a language change on the next right-click (upstream needs a sign-out for that).

How this fork is maintained

• main mirrors upstream exactly and is never written to; every change lives in a reviewed, tested branch that is merged into dev-main, the branch you are looking at.
• New upstream releases are merged into dev-main (never rebased), so every release tag stays in the history.
• Every push builds all targets on CI, runs behavior tests for the encoding features, and checks the MSI down to its registry entries. Releases are cut by tagging.
• Lang/ is vendored from the official binary release and pinned to a sha256 manifest, so it can be shown to be the official files plus this fork's own strings. See .github/lang/README.md.

Roadmap

• Finish the in-manager code page switching: add progress and cancellation while a large zip or tar is reopened.
• Measure reopen times on large and solid archives (drives whether the switch stays).
• Possibly show the fork release number in the About box.

License

The same terms as 7-Zip: LGPL 2.1 or later, with the unRAR restriction for the RAR decompression code and BSD-licensed pieces as listed in DOC/License.txt. This is a modified build, not the official 7-Zip; the full change history is this repository. 7-Zip is Copyright (C) 1999-2026 Igor Pavlov.