Release 2.01 (Duet 2 series) and 1.22 (older boards)
This is mostly a bug-fix release, with only minor new and changed features. See https://github.com/dc42/RepRapFirmware/blob/dev/WHATS_NEW.md for the change list.
Files DuetWiFiServer.bin and DuetDriverFiles.zip did not change in this release.
Duet WiFi and Duet Ethernet users should install Duet2CombinedFirmware.bin and DuetWebControl-1.21.2-dc42.zip. Duet WiFi owners should also install DuetWiFiserver-1.21.bin if not already running this version of the WiFi module firmware.
Duet 06 and 085 users should install RepRapFirmware.bin and DuetWebControl-1.21.2-dc42.zip.
The Symbols files are not to be installed, they are to help debug unexpected software resets.
UPDATE 2018-08-31: update Duet Web Control to version 1.22.3