# Where to find an online testing environment for specific programming languages?

Here is my scenario.

1. I pose a programming puzzle. It might be golf, or might be something else, but I don't specify the language.
2. Some posts a answer that looks really good, but I don't have a working environment to test it.
3. ???
4. Profit!

Let us compile a list of free execution environments reachable over the internet.

One answer per answer, please, and list the protocol and host as well as as much detail on the available execution environments as possible.

• Just now I'm looking for a ruby 1.9 shell. Feb 10, 2011 at 18:47
• I'd like to know where I can test windows powershell answers Feb 10, 2011 at 22:16
• @gnibbler, sandboxing powershell doesn't seem like an easy proposition. Feb 11, 2011 at 9:18
• also matlab or mathematica Feb 11, 2011 at 11:52
• ...anyone want to set up a VM? :) Feb 18, 2011 at 17:14
• @gnibbler: for matlab some of the answers should work with octave, which is free. For Mathematica there is Mathics, and it also has an online interpreter, but unfortunately that's not that feature-ready :( Feb 13, 2014 at 17:13
• The There's a fiddle for that! site currently lists 26 fiddle sites, some of those supporting multiple languages. Oct 28, 2016 at 12:06

# jq

• https://jqplay.org ­– Not written by the language's developer himself, but the official jq Manual also uses it to run its examples.

jq play is more an interactive playground, so the checkboxes to emulate the command line switches not seem to be settable through GET parameters, like the Filter (q parameter) and JSON (j parameter) inputs can be. (They fixed it. Now it can generate a permalink with the complete setup.)

• https://jqterm.com/ – “an alternative interactive jq web terminal with autocomplete (and faster querying with large datasets as they're cached online in private gists).” (According to jq recipes).

# Chicken

The language's homepage has an interpreter built-in.

# .NETFiddle

If most of the time, I will use Tio for .NET snippet. It is good to know about .NETFiddle.

• .NETFiddle supports C#, F# and VB.
• .NETFiddle compiles with .NET 4.5 or Roslyn 2.0
• .NETFiddle allows to use NuGet Packages !

## Wren

There is an online interpreter for Wren called "the Wren Nest".

# Scastie

Scastie is a free, no-account-required sandbox for running Scala code. It's particularly good for testing short snippets, since code doesn't need to be contained in a class/object or method. In worksheet mode, when a snippet is executed, each expression's value and type are displayed next to it; you can also use print and related functions to output to the console as usual. Scastie generates permalinks (like so) and supports both Scala 2 and Scala 3. You can also sign in to Scastie using your GitHub account so you can access your saved links more easily.

## Pyke

Online: pyke.catbus.co.uk

# CGL (CGL Golfing Language)

There is a CodePen online interpreter for it.

# Fourier

Whilst also available on http://tryitonline.net, the full version of Fourier (with delays and screen clearing) can be found permanantly on http://beta-decay.github.io/editor.

# QBasic 1.1 at Archive.org

Real QBasic--sound, graphics, everything--running in DOSBox, available in your browser. Caveats: there's no copy-and-paste, so you have to type your code by hand, and I haven't found a way to break out of infinite loops (short of closing the browser and starting a new session).