Quintel does all its product development in-house. Our team of developers has written the calculation engine for the Energy Transition Model entirely in the Ruby programming language. This language is a dynamic, reflective, object-oriented language with an active open source community. For the ETM it offers a readable way to create, maintain and expand our modules.
Where possible we use off-the-shelf products, such as compass, sass, less or bootstrap, and, if necessary we build our own tools, such as:
Everybody at Quintel uses our Git repositories, which we use to store our applications (we have around 10 under maintenance, from very big to extremely small). We also maintain research data in git repositories, so that we can work with branches, do git greps, and such.
Having a product that is under development for years already and for years to come, it is imperative that we have a code base that is properly tested.