This might be a question people already asked or is obvious to experts, or is not appropriate for this forum, if so, I apologize. I am trying to calculate things like $z/(e^z-1)$, or find the inverse of $x=z+ 2z+5z^2+\cdots$, expand as power series. What is the best (or favorite) software package you use to do stuff like this?
Okay, I've gathered the answers from the comments in alphabetical order.
flint has the fmpz_poly_revert_series command (A web search revealed a reference pdf, but no web page). Some benchmarks seem to indicate that flint is unusually fast.
Pari/GP has the serreverse function.
For the TI-nspire CAS calculator: http://www.ticalc.org/archives/files/fileinfo/424/42499.html.
Maple produces it. See http://www.maplesoft.com/support/help/Maple/view.aspx?path=powseries , especially the command http://www.maplesoft.com/support/help/Maple/view.aspx?path=powseries%2freversion for info.