php/php-src

Prefer this fork only if you need a long-lived custom PHP source base and can absorb the maintenance cost. If you want current upstream PHP behavior, this fork is too far behind.

Prefer this fork only if you specifically need its historical downstream runtime/JIT behavior and are prepared to own a very stale codebase. For most adopters, upstream PHP is the safer choice.

Choose this fork if you want a customized PHP engine and are comfortable owning a large downstream patch set. Choose upstream if you want current fixes, lower maintenance risk, and maximum compatibility.

Adopt this only if you specifically want an almost-upstream PHP source tree and are comfortable inheriting upstream lag; it does not currently show any fork-specific value add.

Choose this fork only if you specifically need its custom engine and library changes and are prepared to maintain a heavily divergent PHP tree. For most adopters, upstream PHP is the safer choice because this fork is stale, far behind, and likely to require substantial maintenance work.

Prefer this fork only if its downstream changes are specifically useful to you and you can maintain a large rebase gap. If you mainly want a current PHP interpreter, upstream is the safer choice.

Prefer this fork only if you specifically need one or more of its local patches and are prepared to maintain a large downstream delta. If you want current PHP behavior, security fixes, and low maintenance overhead, upstream is the better default.

Choose this fork only if your goal is Docker-oriented PHP packaging and you are comfortable inheriting an old, heavily diverged codebase. For anything that needs current PHP runtime behavior or active upstream maintenance, upstream php/php-src is the better choice.

Prefer this fork only if you need its specific downstream patches or generated-data changes and are willing to own a stale, heavily diverged PHP tree. If you want current PHP behavior, security posture, and easier maintenance, upstream is the better default.