Go to jsfiddle.net
Run and share .NET Visual Basic and C# code. Currently supports console projects.
Go to dotnetfiddle.net
Test your SQL in sqlite3 running inside the browser.
Go to sqlite.org
Play around with database, create your schema and test SQL. Supports number of databases,
currently MySQL, Oracle, PostgreSQL, SQLite and MS SQL Server
Go to sqlfiddle.com
Confronted with a problem, you thought "I know, I'll use regular expressions."
Now you have two problems. regex 101 to rescue!
Go to regex101
This one does not follow the official naming convention but compiles and runs code
written in various languages. Checkout the supported languages from the top menu bar.
The list is exhaustive, from Ada to Verilog via Brainf*ck and other more or less
well known languages.
Go to TutorialsPoint.com
Interactive GCC compiler
This is not a regular fiddle. Instead of letting you execute c/c++ code the interactive
compiler compiles your code and then show the assembler code. This lets you investigate
what kind of machine code is generated for certain structures with specific compiler flags.
Go to gcc.gobolt.org
Go to REPL
Logo Interepreter by Joshua Bell runs logo programs directly in your browser. To get started,
paste some example code from the right side to the field next to "Run" button and hit run.
Go to Logo Interpreter
Getting your next big thing out with Brainfuck can sometimes be a bit overwhelming. But no worries, with this tool you can easily
step through the app.
Create your own web salad by mixing your choice of markup, style and programming logic. FiddleSalad supports
various languages for each part.
Go to FiddleSalad
Environment for writing and executing Rust programs.
Go to Rust Play
Play around with ZK Java framework for building web applications. Create UI, write Java code. Run and Test.
Go to ZK Fiddle
Nice an clean environment for trying out Go, the statically typed language developed originally at Google.
Go to Go Fiddle
Test your Swift code with various versions of Swift.
Jump to sandbox
oK is a learning environment for the K programming language
In case your K-skills are a bit rusty, check out the oK documentation
The thing is open source, so you can also run it on your own machine.
Code goes left, results come right. Easy as that to test your PHP code. PHP Tester supports multiple versions
from age old 5.x to (almost) latest and the greatest.
Run PHP Tester
Practise your Scala skills in the interactive playground.
This way to Scala
Quite comprehensive looking PHP playground with different frameworks and even debugger.
Fiddle with PHP
Play around with interactive C++ shell. Supports also stdin for your "Hello, [your name here]" fiddling purposes.
Back in the days ColdFusion was the thing.. In case it's still for you, this is something to try.
This one keeps it plain and simple. Your ColdFusion code on left, results on right.
Vyxal online interpreter
Vyxal is a language developed for code golfing. And as the developer puts it,
"[It] takes the idea that conciseness comes at the cost of practicality and throws it out the window"
This site will help you develop, run and share your Vyxal creations.
Sentinel is a policy as code framework from Hashicorp, embedded into enterprise versions of Consul, Nomad, Terraform and Vault.
With the playground you can learn the framework or prototype new functions and policies.
Play with Sentinel
Write SQL scripts, test your queries. Support many databases, like MySQL, PostgreSQL, Oracle, Microsoft SQL Server.
Sqlize your query
Test your PHP 5.x, 7.x or 8.x code against various databases such as Oracle, MySQL and Postgres.
Play around with many versions of Postgres, MySQL and Sqlite. Pro version available
for private fiddling needs.
Fiddle with DBs
Setup your data, run your queries and check results. Easy as that!
Play with MongoDB
.NET XSLT Fiddle
Test your XSLT transformations with couple of different engines.