A lot of the routine development discussion takes place on the Firedrake slack workspace. This channel is open to all, but you’ll need to request an invitation; see this page for instructions. Once you have access you can then join the icepack channel. If you’re using icepack regularly, this channel is where we’ll announce important changes like bug fixes or fancy new features.
You can also email the lead developer of icepack, Daniel Shapero, at the address listed here. If you have questions that aren’t answered here, or you want to get involved and don’t know how, please reach out. See the Development section for more background on the internals of icepack and how to contribute.