The post that contained the seed of Technic was made on 09 August 2011:
The first actual 'release' was a month later, on 05 September 2011. It was a .rar file that you had to open and drag the contents into the minecraft.jar, just like all the sad and pathetic people on the minecraft forums have to do because they hate 'ease of use' and 'accessibility'. You even had to delete META-INF yourself!
The first 'Launcher' release was a further month later, on 01 October 2011. The Launcher was the old Yogbox launcher with the serial numbers filed off. It is the first version of Technic that did not include Better Than Wolves, after the discovery that you could not disable it without causing gamebreaking crashes (the core code for fire was modified by BTW, so if it was removed manually lightning would crash the game). I'm the one that posted the bug report about it and Power Crystals was the one to figure out exactly why I was crashing.
The first multiplayer release (then called Technic MP as it was not ported to Bukkit) was on 27 October 2011.
Tekkit was released on 31 December 2011. Remember that all of these mods had to be installed on separate minecraft directories that you had to either make yourself or rely on something like the Minecraft Profile Manager in order to use.
The Technic launcher as we know it was released on 09 February 2012, although screenshots of the Launcher were posted on 12 December 2011.
I'm not telling you what versions of minecraft each of these worked with because fuck you. Hope this helps!
