While the documentation isn't explicit, I'm finding most evidence suggesting that there will be 100 greenlets working concurrently, each with its own connection. This has also been supported by two people in the "#eventlet" channel on freenode, which I recognize may not be the most reliable source. However, one of those two people is one of the original 2 authors of eventlets, so that's more credible than your average freenode lurker. Entire conversation below:

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`<mhrivnak>` Hi, I could use a little help understanding how eventlets work. I'm looking at the web crawler example: http://eventlet.net/doc/examples.html#web-crawler
 Does the size of the GreenPool == the max number of concurrent green threads that can run?
 And thus there could be as many as 200 open connections at one time in this example??
`<teepark>` yes, it's the pool size
`<mhrivnak>` Thanks teepark. That's what I suspected, and I know it seems obvious, but it's helpful to get confirmation.
`<teepark>` np :)
`<fzzzy>` mhrivnak: that's the max green threads that the pool will use. you can still have other pools, start your own green threads, etc
`<mhrivnak>` Thanks fzzzy. We need to download a large number of large files with some concurrency, and I wanted to make sure this is the correct place to be limiting the number of concurrent downloads.
`<fzzzy>` mhrivnak: yeah that's what pools are designed for