Modern HTML+CSS is more than enough for most academic posters:
.. image:: docs/tutorial/logo.svg :align: center
See it in action on a real example <https://cpitclaudel.github.io/academic-poster-template/koika/poster.html>
and follow the tutorial <https://cpitclaudel.github.io/academic-poster-template/tutorial/poster.html>
to create your own posters.