Just started to play with the ESP8266-01 modules. Purchased from Taobao.
These, I believe, are version 2 and have the LEDs near the antenna. When first started they identify themselves as [Vendor:www.ai-thinker.com Version:0.9.2.4] and are version 018000902-AI03. This is a custom firmware from ai-thinker.
There seems to be quite a few different versions of similar modules. And the same module could have one of several firmwares.