Mostly what I anticipate I will need for the job. For my own pleasure I choose tools whose proponents talk with a reasonable voice. I dismiss any technonology when I see people that:<p>* Says that the rest of the world is doing it wrong and they will fix the situation with this &quot;change of paradigm&quot;.<p>* Presents their products as a &quot;social movement&quot; that&#x27;s &quot;challenging the industry as we know it&quot;.<p>* Promises 10x productivity.<p>* In general, bases their success on attacking others. Specially if they say things like &quot;everybody knows exceptions are like cancer&quot;.<p>* Uses grandilocuent names to call a two thousand lines library.<p>* The resulting code looks like gibberish. The most likely a child can understand it, the better. It it&#x27;s directed at the elite programmers, bad.<p>* Doesn&#x27;t put enough care on tooling.<p>Edit: OK, it&#x27;s a very negative answer, but it&#x27;s effective. It quickly discards 99% of shiny new things.