Roadmap declares the intention to move from custom web fetcher to something more standardized. At selfoss, we are currently in the process of doing the same so we would like to help with this for our dependencies, including SimplePie.

Since selfoss targets PHP 5.4, we would need to use older version of Guzzle (5.*), which might cause conflicts for applications using SimplePie and a different version of Guzzle. For this reason I propose depending on a HTTPlug interface and letting the application choose the network library.

If you do not have any objections I will start working on it.