I got one of the Jaycar ones and it came loaded with the AT firmware, so I been using pretty much any ESP-8266 compatible code and it works fine.
There's a link to the firmware http://www.jaycar.com.au/medias/sys_master/images/h9a/hcf/8893355589662/XC4614-firmwareMain.zip, but it also has sample code and info about flashing the firmware or using it as a standalone board with the IDE.
One of the firmware images seems to behave like the board documented in the other link (DOIT firmware).