Pd-port of the Max/MSP-port Juhana Sadeharju's Gigaverb.
You can download everything directly from Deken.
Thanks to Fred Jan Kraan for his work on [gigaverb~]: https://github.com/electrickery/pd-gigaverb
Update (27/12/20):
- add 64 bit support;
- update to latest pd-lib-builder