They all print a joke about asexuals:

• stripe-1.cr was tested in the Crystal playground.

• stripe-2.php can be tested using the HHVM Docker image.

  $ docker run --volume $(pwd):/var/www/public --publish 8080:80 hhvm/hhvm-proxygen:latest
  $ curl http://localhost:8080

• stripe-3.tf can be tested using the Terraform Docker image:

  $ docker run --volume $(pwd):/src --workdir /src hashicorp/terraform:light apply

• stripe-4.fs was tested in an interactive session with the F# Docker image.

Idea shamelessly copied from spacekookie/gay (rainbow pride flag) and ticky/trans (trans pride flag).

ozh/github-colors, for finding appropriate languages for each colour.