Hello,
We understand that you want to develop and rewrite code in Javascript an secure it, also you want to develop addons browsers.
We are the team of UI, Java and PHP developers. Our skills include HTML5, CSS3, Javascript/jquery/ajax, PHP/Mysql, JAVA etc...
We have UI developers who have strong experience in Javascript, also having experience in Javascript code security. Also they have experience in developing browsers.
For rating purpose you can check our freelancer profile.
Let me know if we can discuss now on your project. We prefer Skype/IM for faster communication.
Looking forward to hear from you soon.
Best!
Ruchi