Can be submitted as GitHub issues.
pollen-count: enumeration and cross-referencing library by Malcolm Still
Pollen mode: Emacs mode for Pollen by Shrutarshi Basu
Pollen Component: Component-based development for Pollen by Leandro Facchinetti
CSS-expressions: S-expression-based CSS by Leandro Facchinetti
Yes, the source for Typography for Lawyers is available. In terms of content, TFL was originally the basis of Practical Typography. But in terms of code, this new TFL website is essentially a clone of Practical Typography, but rewritten to be clearer and more instructive, with extensive source comments. [source]
A Poor Guide to Pollen by Ahmed Fasih