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Half a year later I'm still publishing stuff. Yay, what a fucking breath of fresh air.
In case you haven't noticed, they're shutting down CodePlex Archive. I've set to back that thing up without a second thought. I wrote a tool to help facilitate this effort. When the process is done, I'll probably host a website allowing everyone to browse the archived projects for free. Impatient? You're free to build the tool and download a copy of the archive for yourself.
In case you don't like .NET and/or C# for some reason, the search API usage should be clear, it's located in the file called ProjectArchiver.cs
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An important note: their search API allows to skip up to 100,000 projects for any search query. Not sure if there are more, but I'll be sure to provide an update when I figure it out.