What I would use and languages that applicable aren't the same. I'd probably use OCaml. But almost anything is better than C/C++ for this domain. If the goal was to get as many programmers, with the widest distribution, Java 7 would be an excellent choice. RoboVM can compile to native for the platforms that don't have the required runtime. Others might use Rust, ATS or Idris. Hell, even Lua with a small C core (NACL, os calls, etc) would be better.

The red herring that gets trotted out is timing and side channel attacks, crypto itself can still be done in nacl. But everything else, GUI interaction, network interaction and parsing of external data should be done in a safe language.

Obscure != secure.

The same argument has been said for Java (but turned out to have worse problems in practice), Ruby (where if you every wrote something in Rails you've been vulnerable halv a dozen times by now) and PHP (and any commentary here should be unnecessary).

Sure, all the obscure languages you mention which never had even one project with a fraction of the usage base of Apache or Postfix may have no known security problems, but that's not a something to boast about. If you really want these languages to succeed, build a project with the potential user base of Nginx or Linux. Just don't complain about other's language choices, especially not when those are well known and well understood ones.

Mozilla and Samsung are building the Servo rendering engine, based on Rust.

Everybody and their cat knows that. It's also not a functional web browser yet, and doesn't have a measureable market share compared to Firefox and Chrome, which are C++. Let's compare CVEs when it's at least in the top three. But if it survives one day at cansecwest I would be thoroughly impressed.

Well it's an effort, and several popular libraries are releasing bindings for their products using Rust.

And for two large companies to be working on something as large as Servo, even before the language went 1.0, there must be something good about it.