cd go
# bash set GOPATH
$ export $GOPATH=$(pwd)
# install dependencies
$ go get gopkg.in/mgo.v2
$ go get github.com/go-martini/martini
$ go get github.com/martini-contrib/binding
# run martini
$ go run main.go

$ cd python
# Use python pip to install requirements
$ pip install -r requirements.txt
# export FLASK_APP env
$ export FLASK_APP=main.py
# run flask
$ flask run --port=3000

$ cd ruby
# use gem to install bundler
$ sudo gem install bundler
# use bundler to install dependencies
$ bundle install --path vendor/bundle
# run sinatra
$ bundle exec ruby main.rb

$ cd node
# use yarn or npm to install packages
$ yarn install
# run express
$ node index.js