Learn by example: cssreference.io is a free visual guide to CSS. It features the most popular properties, and explains them with illustrated and animated examples.

Swagger is a powerful open source framework backed by a large ecosystem of tools that helps you design, build, document, and consume your RESTful APIs.

I love newsletters, but I hate receiving e-mails. Call me an oldie, but I still use RSS feeds to read my news and e-mails for communication. And I prefer to keep those two separate.

Unfortunately, as newsletters have become popular, there are some great readings that are not available through RSS anymore. Kill the newsletter! exists to fill this gap.

This service converts newsletters into RSS feeds.

Interactive code to flowchart converter. Turn your workflows, algorithms and manuals into easy to understand diagrams via simple code.

Run a free website speed test from multiple locations around the globe using real browsers (IE and Chrome) and at real consumer connection speeds. You can run simple tests or perform advanced testing including multi-step transactions, video capture, content blocking and much more. Your results will provide rich diagnostic information including resource loading waterfall charts, Page Speed optimization checks and suggestions for improvements.

Free PCRE-based regular expression debugger with real time explanation, error detection and highlighting.

Webhook Tester allows you to easily test webhooks and other types of HTTP requests.

Crossbar.io is is a router for the open WAMP protocol, and it is open source. Together with the open source WAMP client libraries it is a connection fabric for components in distributed applications.

Crossbar.io connects an application with a temperature sensor, backend, alarm lamp, mobile frontend and a fan

Components can e.g. be a Web page/Web app frontend, a classic application backend running on a server, an individual microservice, a mobile client, or an IoT device.

Whatever they are, all components connect to Crossbar.io and Crossbar.io enables them to communicate with each other as equals.

GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. GraphQL provides a complete and understandable description of the data in your API, gives clients the power to ask for exactly what they need and nothing more, makes it easier to evolve APIs over time, and enables powerful developer tools.

Increase your form conversions by fixing common usability issues

Enter a URL. FormLinter will find a form on the page and let you know if it can be improved.

The Service Worker Cookbook is a collection of working, practical examples of using service workers in modern web apps.

PPM is a process manager, supercharger and load balancer for PHP applications.
It's based on ReactPHP and works best with applications that use request-response frameworks like Symfony's HTTPKernel. The approach of this is to kill the expensive bootstrap of PHP (declaring symbols, loading/parsing files) and the bootstrap of feature-rich frameworks. See Performance section for a quick hint. PHP-PM basically spawns several PHP instances as worker bootstraping your application (eg. the whole Symfony Kernel) and hold it in the memory to be prepared for every incoming request: This is why PHP-PM makes your application so fast.

Auth0 is a service that abstracts how users authenticate to applications.

You can connect any application (written in any language or on any stack) to Auth0 and define its Connection, the method used to authenticate the users of that application:

Custom credentials: username + passwords
Social network logins: Google, Facebook, Twitter, and any OAuth2, OAuth1 or OpenID Connect provider
Enterprise directories: LDAP, Google Apps, Office 365, ADFS, AD, SAML-P, WS-Federation, etc.
Passwordless systems: TouchID, one time codes on SMS, or email

Grafana provides a powerful and elegant way to create, explore, and share dashboards and data with your team and the world.

Grafana is most commonly used for visualizing time series data for Internet infrastructure and application analytics but many use it in other domains including industrial sensors, home automation, weather, and process control.

Natural Language Interface for apps and devices. Build bots easily. You tell us what your user said, we tell you what your bot should do next. Your users give us voice or text, you get back structured data. It's that simple.

A JavaScript framework for building data-driven React applications.
Never again communicate with your data store using an imperative API. Simply declare your data requirements using GraphQL and let Relay figure out how and when to fetch your data.
Queries live next to the views that rely on them, so you can easily reason about your app. Relay aggregates queries into efficient network requests to fetch only what you need.
Relay lets you mutate data on the client and server using GraphQL mutations, and offers automatic data consistency, optimistic updates, and error handling.

Open source continuous delivery server to model and visualize complex workflows with ease. Automate and streamline your build-test-release cycle for reliable, continuous delivery of your product.

Packer is a tool for creating machine and container images for multiple platforms from a single source configuration.

Ember.js is an open-source JavaScript web framework, based on the Model–view–viewmodel (MVVM) pattern. It allows developers to create scalable single-page web applications by incorporating common idioms and best practices into the framework.

Phoenix is a web development framework written in Elixir which implements the server-side MVC pattern. Many of its components and concepts will seem familiar to those of us with experience in other web frameworks like Ruby on Rails or Python's Django.

Phoenix provides the best of both worlds - high developer productivity and high application performance. It also has some interesting new twists like channels for implementing realtime features and pre-compiled templates for blazing speed.