WDLXTV_G1 is for the original WD TV HD
WDLXTV_G2 is for the WD TV HD Gen2
WDLXTV_LIVE is for the WDTV Live - NOT the GEN3
WDLXTV_PLUS is for the WDTV Live+
Flash = flashable version
Ext3-boot = disk-based version (requires to have any version of WDLXTV already flashed)
WDLXTV's can be based on any number of official firmware. The first section is the official baseFW.
means the firmware is based off official firmware 1.02.21.
For specific differences between official bases see here