While I think about it, if I choose the environment in which I develop, I don't think the company can necessarily force me to use their dev tools or languages.

If the requirement is to produce a library that can support certain business functions, why should it not be developed using whatever technology I am most comfortable using? Providing it works in the run-time environment, everything else should be my choice.

And yes, development licenses for some software are expensive.

Try adding up Visual Studio, Altova XML Spy and Embarcadero ER-Studio to name 3 of the tools I routinely use.