Actually, Torch (2002) is older than Theano (2007). Moreover, both were already used widely in the research community. Tensorflow was actually late in the grand

Actually, Torch (2002) is older than Theano (2007). Moreover, both were already used widely in the research community. Tensorflow was actually late in the grand scheme of things, but replaced Theano and to some extend Torch (which used Lua for its public API). I think it's fairer to say that Tensorflow is the first implementation that had wide adoption outside academia.