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Request for Comments: PECL Versioning
Currently, PECL versioning is fairly anarchic. It is impossible to determine the status of an extension, or whether an update will break binary compatibility with previous versions (or work with a given PHP release) without a long try-&-fail process. Windows PECL binaries should have reliable version information in the DLL resources (physically visible in the file properties) as well as at runtime (through phpinfo(), phpversion('extname') etc.). Some of the processes in php.net that currently use hard-coded lists could also benefit from a standardized versioning process. This problem has to be fixed to bring PECL to a higher quality and reliability level.
There is actually two RFCs (proposals) to deal with version number in PECL and for the PHP extension in general (core).