where?

• github/cactus
• other places

projects?

• go-camo
  Go version of Camo server.

• go-statsd-client
  A Go client library for StatsD.

• mlog
  A purposefully basic logging library for Go.

• gostrftime
  A Go pkg for formatting time. Time in an strftime(3) like way. Basically, strftime for Go, with a couple of additions.

• tai64
  A library for parsing and formatting TAI64 time.

• go-misc
  Some misc go libs: chrono, set, tally.

• pyermc
  Python memcache library. Supports text and binary protocols.
  Also on pypi.

• siphashc
  Python siphash c module. Wraps the siphash from floodberry.
  The pypi package and project maintenance has since been handed off.

Contributions to other open source projects?

• python-memcached - commits
• socketpool - commits
• requests - pull-request and fix (note: history on the project is odd due to some merge squash of master & develop apparently)
• pymysql - commits
• sinatra - commits
• hugo - commits

There are others that were either not notable, or the author chose to implement the solution in a different way.

I will add more stuff here later, mostly likely.
Until then, check out github/cactus.