I am not the o.p. but: the success of Unix helped the success of C, JavaScript succeeded because Netscape made it the only one on the browser, C++ won the war against Objective-C as the "object-oriented successor of C" because Microsoft embraced it and they had a lot more power than Next (that embraced Obj-C). Python did sustain its fight with Ruby (and PHP) for the role of "sane successor of Perl" because Google provided so many libraries and frameworks.