Where to get the sources

From Proxmox VE

Since Proxmox VE is Open Source, you can access all the source files for the distribution at the following URL:

Proxmox VE 1.x:

• ftp://download.proxmox.com/sources/

Proxmox VE 2.x and higher:

Beginning with Proxmox VE 2.0 beta, all code is available on https://git.proxmox.com