ownCloud (OS, SH)
ownCloud is a complete self-hosted service platform that provides file sharing and collaboration features including calendaring, to do lists, a document viewer, and integration with Active Directory and LDAP. The software also includes a feed reader application, which started as a Google Summer of Code effort and takes many design cues from Google Reader. While ownCloud News is not installed by default, as it is still in the experimental phase of development, the developers expect to have a stable version ready well before Google Reader shuts down on 1 July.
Like ownCloud itself, the feed reader is licensed under AGPLv3 and its source code is available on GitHub. Installing an ownCloud instance for the single purpose of using its feed reader seems overkill, using it might, however, be an option for those who are already running ownCloud or are thinking of installing it for other reasons. The News app already has a solid set of features and the developers seem committed to getting it production ready before Google turns the lights off for its reader.
For corporate users, ownCloud also has commercial support options available.
Gregarius & Feed on Feeds (OS, SH)
Two other open source web-based feed readers, both licensed under the GPLv2, are Gregarius and Feed on Feeds. Both projects are older and have not seen much development activity of late. They both run on typical LAMP setups, but are visually not as pleasing as the aforementioned alternatives; they are also not as feature complete. Because of the relative inactivity of their code bases and because neither have compatible mobile applications, I would suggest trying one of the other alternatives first.
Fever (P, SH)
Shaun Inman's Fever is a proprietary web-based feed reader which, rather uniquely, is built for self-hosting; there is no hosted service available. Instead, for $30, users get the application (as well as any minor updates to the version they have purchased) and can install it on their own server. The application's interface also presents a different take on the concept of feed reading. By default, it hides unread counts and arranges news items by "temperature": a particular news item is "hotter" the more it is being talked about. To assess the temperature of stories, Fever aggregates topics among a number of feeds. Unlike traditional feed readers, Fever therefore gets easier to use the more feeds a user adds. The more sources the software has available, the better it can assess what stories are the most important, which allows it to arrange them in the interface accordingly.
When we tested the software some time ago, we found that Fever's approach is very appropriate for users who want to aggregate a large number of feeds and get an overview of the most talked-about stories in a short time. It is not necessarily useful for users who monitor a smaller number of feeds, but do not want to miss items from these feeds, or for users who are interested in less talked-about stories. For these users, NewsBlur's adaptive filters might be better suited to sift through a large number of feeds.
Fever has been available since 2008 and has been optimised for mobile phones (specifically the iPhone), but it still lacks dedicated mobile applications, especially for tablets. The software has not been under very active development lately. After Google's decision to discontinue Google Reader became public, Inman said that he currently has no plans to add new features to the application as he is busy with other projects at the moment. For users looking for a truly different alternative to Google Reader, Fever is certainly an option if they are willing to install an instance themselves, but individuals who are looking to mirror the functionality of Google's service as closely as possible should consider one of the other alternatives.