Anyone can compare the "externals" in SVN with "submodules" in git? I'm curious since I'm used to externals in SVN and they're ok but as always you have to keep some things in mind
* The submodules aren't automatically updated like externals are with "svn up", you need a second command.
* Adding a submodule is done with a command, not editing files/props directly.
* Any changes to the pinned revision are done inside the submodule (git pull, new commits, etc), which automatically changes the reference in the parent repo and then is committed in the parent repo.
* Removing a submodule is two commands now, not a bunch of manual work (article is out of date: https://news.ycombinator.com/item?id=26171333 ).