Maybe the increased number of people on the internet is connecting those who are making open languages. (I know the poster listed many ones made by closed teams too.)

I thought the technical/scientific computing market that MATLAB serves was too niche to get critical mass in an open competitor that could surpass it. I saw Octave as always being a second place clone playing catch up. I don't know what it took to get it going but Julia has me very excited and I'm grateful for the team that chose to make it.