There are tens of thousands of open source projects in the wild, but how do
you determine what’s good and what’s not? Simply looking at the popularity of a project on SourceForge.net is enough for some, but with the increased diversity of open source code repositories, that’s not going to cut it for the rest.
Ohloh, a resource for open source intelligence on thousands of open source projects, has up-to-date information on open source projects and the people who
develop them, Scott Collison, CEO of Ohloh, told
Ohloh collects software metrics from a variety of sources, including the
project’s source code and the software development infrastructure used by
the project’s development team. The site provides information about
lines of code, licensing and languages in a project, as well as stack information about open source projects people use and in
The Ohloh site also estimates what it would cost to
develop a project.
For example, for Mozilla Firefox, Ohloh has calculated
that there are 364,376 lines of code. According to Ohloh, that would take
95 “person years” of effort to complete. At an average salary of $55,000 per
year per developer that translates into a project cost for Firefox of nearly
Ohloh also rates open source
projects. “We offer a project summary that will warn you if a project is an outlier,”
Collison explained. “So for example, if we don’t see any development activity
for six months, we give you a warning.
“Ohloh lets you know whether a project is average, below average or above average.”
A common refrain among open source detractors is that most of the open
source projects on the SourceForge open source repository are abandoned
efforts. Ohloh gets around that issue but not by relying on SourceForge for its
“Their activity rating is based on how people are interacting with the
project just through the lens of Sourceforge,” Collison said. “We need
something consistent across all forges.”
To that end, Ohloh spiders the Web, extracting information from CVS, SVN, GIT
and other source-control repositories, and then it normalizes that information
for use by Ohloh. The Ohloh popularity index is then based on that wider
Though Ohloh is all about providing information on open source code, Ohloh
is not an open source effort yet. Collison said the Ohloh code is an internal effort but it does intend to open source its data-collection tools.
“Right now we’re heads down on making this stuff and we need to be
thoughtful about cleaning up the code and having good documentation for when
we release it,” Collison said.