Our preferred server-side programing language is Python. We have used a number of web-frameworks in the past. We have written our own sometimes. At present, we use Flask, Pylons and Pyramid Python web-frameworks. We use modern front-end stack with a focus on ReactJS.
PostgreSQL and MySQL are our favorite databases. In our opinion, SQLite is also a cool technology.
Our preferred technology stack is platform independent. However, we feel at home when using Linux operating system.