I have an instance of crafter running with crafter-studio-publishing-receiver-2.5.3-aio.jar, I need to locate the source code for the jar file.
Is this the right repository
What is the significance of the word "legacy" in the name of the project?
You can find the source code here: https://github.com/craftercms/legacy-deployer
The specific version can be found by checking the manifest of the jar. - unzip the jar - open ./META-INF/MANIFEST.MF - locate the property Implementation-Build: 87c84d58313b2bcbdca306de69758320aee174d0
This value can be placed in github to get the exact code you are looking for.
Example:
https://github.com/craftercms/legacy-deployer/blob/87c84d58313b2bcbdca306de69758320aee174d0/cstudio-publishing-receiver-zip/pom.xml
The reason we renamed the project "legacy-deployer" in github is that with Crafter 3.x we are moving to a new deployment system. Without going too deep on this: The new system is based on Git pulls, as you can imagine, this approach has many benefits. It will support the same concepts (callbacks etc) as the now "legacy" deployer.