Today, we are thrilled to announce CodeMirror as the new code editor on Replit for mobile devices. CodeMirror is a versatile code editor that has been specifically designed with mobile in mind, providing an excellent touchscreen experience. This change is the beginning of a focused effort on mobile development here at Replit; the editor is just the first step! The editor supports all the features you expect from a code editor, and we're working on making it even more powerful.

Replit enables coders to build apps quickly. With nothing but a browser, a developer can spin up a server, store data in Repl DB, and authenticate users using Repl Auth. However, until today, users had to string together all these components to build an app. This is why we're excited to announce replit.web, a Python framework focused on making apps quickly. Building an app with user auth and persistence has never been easier:

One of the most powerful aspects of Replit is the ability to collaborate with friends and peers in real time. When we first added support for multiplayer, we set out to make it as easy as possible to code with others. Since then, collaboration has become an integral part of our product with the release of features like threads and draw.

A couple of months ago, we announced our intention to create a new collaborative program comprehension experience for your repls. This project isn't just about figuring out what's wrong with your code, but really understanding what's going on, together with the people you work with. Today, we are happy to announce that we're releasing the first phase of this experience: a Replit-native, zero-configuration, multiplayer-friendly, interactive debugger for C, C++, Node.js, Python, and Java repls!

The Backstory

In October of 2020, Meghan, our people person, messaged me asking if there was a professional-looking URL shortener. Over the next 48 hours, I created Replit.sh, a URL shortener for use by the Replit team and published it on Github for anyone to use. For the past few days, I have been working on rewriting the entire system from the ground up and so it just made sense for me to make a tutorial on how it is done.

At Replit, our mission is to make programming more accessible. We provide people with free compute in the cloud so that they can build apps on any device. Among the most popular ways to create apps on the web today is React. Historically, however, React tooling has been slow on Replit. While the JavaScript ecosystem has produced excellent tools for professional developers, many of the most popular ones, like Create React App and Webpack, have become increasingly complex and inefficient.

Earlier this year, we decided to close the #1 most requested entry in our Canny board, which requested to improve our previous debugger so that it could also work with multiple files in a project. This was done because it became very clear that there is a need to have better tools to aid with program comprehension built directly into Replit. But we also realized that we could go even further. Even though most of our users could be happy with a traditional debugger experience, our mission is to give people computer superpowers! So today we are announcing that we are working on a new, reimagined, collaborative debugging experience (or maybe we should call it a "program comprehension experience?").

Replit is the go-to place for a lot of people to build their applications. People build chatbots, web applications, games, and so much more. Naturally, projects like this need to maintain sensitive information (secrets). Today we're announcing a new and improved way to manage secrets.

We know that games are an important part of our commitment to making programming more accessible, more creative, and more fun. Back in February when we announced a significant revamp to our graphics stack, we also promised that we would also provide system audio integration. That support is finally available today, as an opt-in feature.

Have you ever wished to be able to protect your graphic repls against prying eyes? Starting today, all VNC connections are automatically protected by the same token that keep your connection to the repl secure. There is nothing you need to do, since this is completely transparent.

Games are awesome, making games is even more awesome. I love making games, making games makes me happy, being happy makes me make better games, i hope everyone can be happy and enjoy making games! -- me, today

It's always been super fast to start writing markdown in a repl. However, the more we used it, the more we realized there were some key features we were missing that would make our lives easier. Which is why we're excited to announce all of the new improvements we've made to the markdown editing experience on Replit!

tl;dr In the next few days, we'll be moving domains from "repl.it" to "replit.com." Nothing is required on your end -- all urls will automatically redirect and you'll remain logged-in (as if by magic). Nothing else changes. We prefer if people referred to us as "Replit" (pronounced rep-lit 🔥). To understand the origins of our name and how we got here, it's useful to tell you the Replit genesis story:

A few months ago, we announced Annotations for our education users, a feature which lets Replit collaborators highlight code and discuss it in context.

Unit testing is a powerful way to verify that code works as intended and creates a quick feedback loop for development & learning. However, setting up a reproducible unit-testing environment is a time-consuming and delicate affair. At Replit, our goal is to give people coding superpowers by demolishing barriers and democratizing access to expert tools. Today, we're launching our zero-setup unit testing environment.

The easiest, fastest way to put a server on the internet should also come with secure defaults. That's why we're excited to announce that Replit is now HTTPS-first, which brings additional privacy, integrity, and security benefits to servers hosted on our platform. This applies to every HTTP server repl on Replit.

Today we're excited to announce that Always On repls are available to all hackers! Anyone with Hacker plan can choose up to 5 repls and keep them running all the time. With Always On, you can for example spin up and host an app like a Discord bot in 30 seconds:

Replit has never been just about code.

Philosophically, Replit and Rails are incredibly aligned. We both exist to remove excessive configuration and complexity that stands in the way of building things. However, for a long time, it bothered me that Replit didn't work well with Rails because we focus on small and lightweight projects. Recently, our infrastructure has gotten much more powerful, and I decided to give Rails another spin. It turns out it's not only possible to do Rails on Replit; it's quite a delightful experience. It takes less than 30 seconds from starting a project to seeing the welcome screen:

We have reimagined the native graphics experience on Replit. Our community of educators and hackers have given us immense feedback on graphics performance and reliability.

Since we introduced native graphics in the browser in 2019, our community has built awesome games and programs in LÖVE, Pygame, and Java Swing. Being able to write some code and see the results right away is what Replit is all about. That and finding peace in a bouncing DVD logo:

Great news! We just made it a lot easier to have conversations about code. You can now use familiar markdown syntax in annotations and chat.

When we started Repl.it, we set out to remove all friction from getting started with programming. That also meant getting out of the way and letting you code as quickly as possible. As part of that, and for a long time, you could start coding on Repl.it without a user account.

Repl.it is already the best place to build your apps. But there was a missing piece: where do you store your data?

We’re introducing Repl.it Database: a fast, free, and easy key-value store that’s built into every repl.

One of the challenges of adding new functionality to any interface is balancing discoverability with visual clutter. We've written before about how a universal command bar can be a great way to expose features without overloading the UI with buttons. This pattern already works well for us in our mobile interface, so now we're bringing it to desktop! Here's a demo of what it looks like:

Audio brings games and projects to life! Web developers have it easy, they can publish their apps on the web and play audio using the browser API no problem. However, what about those of us that are command-line and graphics apps in other languages? Repl.it is a special place on the web where you can publish any app in any language, but so far it’s been missing audio capabilities because code executes in a container on the backend. This summer, for my internship I set out to solve this problem and make it possible to play audio in any repl in any language. In this post I’ll show you how to play audio in your repl and then I will chronicle the journey that got us here.

This is a guest blogpost by GPT-3, the new AI software from OpenAI. We only gave it the title and "Repl.it" and it generated the following post for us

Emmet is a plugin for many popular text editors which greatly improves HTML & CSS workflow, it's also one that's been requested by many of our users.

Repl.it is a great place for prototyping ideas and starting new projects. However as your projects get bigger, the editing experience starts feeling a little limited. That's why we're exciting to announce that we're adding support for tabs!

Oftentimes when we're sharing a repl with a friend we want to link them to exactly where we are in our project. Well now you can with deeplinking!

Terminals make it hard to copy things: Selecting text works differently to what people are used to, and ^C aborts the current program. Links are hard to use.

I like the process of writing because of how simple and portable the tools are. Regardless of time or place, a way to write things down is never far away. There's very little friction between inspiration and experimentation. I wish writing code was more like this.

When you're deep into a debugging session printing a bunch of here, there, and wat, the output in the terminal can get hard to read. That's when search comes in handy, and that's why we're excited to announce our new terminal search functionality.

Java is one of the most popular languages on Repl.it, and the JVM powers many of our other languages (Java Swing, Clojure, Kotlin). We want to make it as easy as possible to code with other people and build new programs out of programs that already exist. So we've added packaging support for Java!

“Command line interfaces. Once that was all we had. Then they disappeared, replaced by what we thought was a great advance: GUIs. GUIs were - and still are - valuable, but they fail to scale to the demands of today's systems. So now command line interfaces are back again, hiding under the name of search. Now you see them, now you don't. Now you see them again. And they will get better and better with time: mark my words, that is my prediction for the future of interfaces.” [1]

When I think of GitHub I imagine a vast network of people and code; a superorganism that changed how we make software. When I was getting into programming, starting a new project was daunting -- you had to imagine and build everything nearly from scratch. My version of code-sharing was calling my older cousin who was going to college for CS and getting code dictated to me over the phone. When the Internet arrived in my home town, it made hacking on new projects so much more fun. Starting a new project, at least initially, became about discovery:

Coding, people believed, was an activity hackers did alone. While that might have been true in the past, the world is changing. New programmers come online every day and they want to effortlessly work and interact with others while writing code. Yet collaborative coding environments have remained troublesome to setup.

SQLite is now a supported language on Repl.it! Our SQLite support brings the entire SQLite command-line interface right into your workspace. Now you have a simple way to experiment, prototype, or refine your data model with SQL.

When our community members want to provide instructions within a repl, the most common pattern we've seen is in a .txt file, or as a code comment. Users quickly figured out that while they could make markdown files, there was no way to render it in a more readable format. Today, that changes. We're happy to announce that you can now preview markdown in repls!

At Repl.it, we want to provide a top-tier online programming experience in as many languages as we can support. Today, we’ll show you just how we do that.

At Repl.it we live and breathe making software creation easier. With our programming environment, you could start coding in your favorite language in seconds. With live deployments, we made web hosting a breeze. With Multiplayer, we've removed the drudgery from coding with friends. And today, we're excited to bring native GUI applications and game development to the browser.

Today we're announcing the most-significant evolution of our platform — something we've been building towards for a long time that we're thrilled to share with you.

Errors are red,
Outputs are white,
File descriptor injection is bold,
Let me tell you about LD_PRELOAD.

A few days ago we shipped a simple feature that will save our users time in finding and opening files, especially for larger projects. This can even be used without having the file tree visible. Read on to see how to use it and to see a demonstration.

Repl's now provide access to an experimental bash shell via the command palette (F1)

Open-source has revolutionized software development -- it wouldn't be an overstatement to say that it's been the most significant productivity win for developers in the last decade or so. At Repl.it, our goal is to make programming more accessible and what better way to do that than make available to programmers the entirety of open-source packages available at their fingertips.

At Repl.it our goal is to provide state of the art in developer tools to everyone in the world, for free. When we started moving our product beyond a simple REPL and started adding IDE features, we had to invent standards and wrappers around every language tool for our frontend to consume. For every editor feature, say errors and warnings (linting), we had to extend our development protocol with a set of commands and data structures, and then teach our development containers how to wrap the given tool, say Pylint, and our frontend on how to consume it (say annotate the editor with errors and warnings). A similar thing has been happening with IDEs for the past few decades -- every editor had to come up with their in-house ad-hoc protocol, and every tool developer had to build adapters and wrappers for editors to consume.

As you use Repl.it more and more, you often find yourself frequently creating repls for quick testing. On your repls dashboard, you can mark important repls by starring them - allowing you to quickly access them. However, there was no way to surface your best work on your profile - users would have to sift through all your repls to find the one they were looking for - until now.

We recently added some changes to how eval mode/project mode operates. These changes allow you to interact with generated files through the console.

Two days ago we introduced our beta support for React frameworks, ranging from static-site generators like GatsbyJS, to fullstack frameworks like Next.js. Today we're launching a significant performance enhancement that we're calling preboot.

Despite the negative press covfefe around React.js when it first came out, I instantly fell in love with it. The thing I liked the most about it was the component model. Until then the JavaScript community has been trying for years to come up with the correct abstraction for creating reusable modules, but it was always leaky. Because React components are essentially functions, and because functions are the undisputed champion of reusable code, it worked out extraordinarily well. You don't need dependency-injection, or any other modularity hacks, you simply pass props! Also, the virtual dom made it so that components are, by default, protected from other components prying into their internals.

Along with the ability to star repls and tag repls, we now take repl organization one step further with the ability to search through your repls.

At Repl.it we come to work every day to explore a single idea—what if programming just worked? What if instead of fiddling around with packages, configurations, and mismatching versions, you just open your IDE and start coding. What if developers can go from an idea to coding and shipping software with no time in between. What if teachers who want to teach programming don't have to also work as IT administrators. What if students can just code their homework without having to set up the development environment on every computer they wanted to code on.

Repl.it is becoming the platform where developers come to learn and build. With web hosting we also made it possible to host websites and since then we've seen an explosion of websites hosted on Repl.it. Today we're going further by making it possible to deploy servers on Repl.it.

On the heels of our Node.js npm support announcement, we're pleased to announce that we now support Ruby Gems too. We're excited to have the Ruby community join the fun.

Ever since we introduced third-party package support for Python we've seen an explosion of exciting programs on Repl.it. Everything from games to machine-learning applications that just weren't possible before.

People use Repl.it in a variety of ways; some use it for building and shipping applications, while others use it for working on homework, and many others use it as a quick prototyping/experimentation tool. Supporting all these use cases (and more) is something we care a lot about, but up until now there wasn't an easy way to, for example, quickly go back to a project that you continue to work on every day.

At Repl.it our mission is to make programming more accessible, which means our coding environment needs to be lightweight, load fast, and work from anywhere in the world. However, as with so many software projects that evolve with time, we accumulated some bloat (luckily, we haven't included a mail client yet) and quite a few ad-hoc hacks to glue everything together. In this post, we'll go over how we designed our new IDE to have a small core (everything is a plugin), to be easily customizable (even on the fly), and to server-render.

Repl.it is quickly becoming a tool that's used in everyday programming, and our users are building all sorts of amazing programs. One thing that's been missing for a long time is the ability to access the internet from repls. Being able to call APIs or remote servers is something programmers can't live without. That's why we're excited to announce that starting now we're openning internet access for all!

People in our community build awesome games, apps, and websites on Repl.it's web programming environment, but until now they didn't have any easy way of sharing these creations with other people.

At Repl.it we focus on simplicity, speed, and, most importantly, reliability. If you're using Repl.it as your primary or secondary IDE we want you to be confident that the time you invest working on your code will never go to waste.

We are always excited about launching new features and sharing with you, our dear users, what we’ve been up to. For the past few months, Amjad, Mason and I have been working hard and last night we quietly launched the new repl features. These features required a lot of infrastructure and data changes which is always tricky to execute. We ran into some technical difficulties last night with the data migration but was able to bring the site back up and things have been running relatively smoothly since then.

We strive to make the workspace as useful as possible while keeping it intuitive and approachable. We get a crazy number of requests for features every day, not to mention our own ideas. It becomes a challenging balance between feature creep and simplicity. Lately we've added a few of these features that we hope you'll find useful and, if not, you won't even notice they're there.

We're constantly surprised and delighted by the creativity of people in our community. Whether it be games, animations, utilities, or simply snippets to answer Stackoverflow questions -- it's always fascinating to see! However, we haven't done a good job giving credits to authors for their creations.

The label "sessions" is very near and dear to my heart. I vividly remember how Amjad came up with the name and why. After we learned that people would like to create accounts on Repl.it, we were trying to figure out what was the main value proposition for creating an account. Of course, it was saving code! But what do you call a list of code projects saved on your account?

On the heels of Google announcing native Kotlin support on Android yesterday, we thought it'd be cool to get a Kotlin REPL up so that people can try it.

We have discontinued support for react native

Last year we introduced support for importing any Python package from PyPi and -- although we don't have perfect support for all packages -- it turned out to be a very popular feature. That's why today we're excited to continue the roll-out for the rest of our platform starting with web-based languages.

Earlier this week we introduced Haskell support. And now, as promised, we're continuing to add more functional languages. So today we're excited to introduce Clojure. A Lisp dialect that runs on top of the Java Virtual Machine with a focus on immutability.

We heard your requests for Haskell and today we're excited to finally announce Haskell as yet another language we support. We've decided to put our focus on adding more functional languages, starting with Haskell, so you can expect more very soon.

At Repl.it we aim to make the full power of programming easily accessible for everyone. That's why when we designed our code execution service we decided that we would not timebox users' programs or sessions.

Today we're excited to release a feature which shows any files your program creates directly inside the REPL. And any time that file changes it will be updated live in the editor. This can be anything from a text file to a gif.

We recently made it possible to import any package from PyPi. However, people who missed the announcement didn't know this was possible. There was also no good way to search and explore packages.

Debug your Python3 programs from your browser

At Repl.it, our goal is to make programming more accessible, and as part of this we aim to provide the full power of popular programming environments with no setup time. And I don't think it's an understatement to say that debugging is the majority of what we, as programmers, do.

Today, we're excited to introduce lint support for Python3. Where previously you had to run your code, look at the console for an error, find the line number of the error and then find that line in your editor. Now, we'll show you errors and potential mistakes live as you type!

Import any Python Package

At Repl.it, our goal is to make programming more accessible, and as part of this we aim to provide the full power of popular programming environments with no setup time. And no modern programming language is complete without third-party packages.

Ever since the LOGO programming language educators have been using Turtle Graphics to demonstrate the power of programming to their students while making it fun and interesting.

It's no secret we're big fans of REPLs. We believe that immediate access to the programming environment accelerates learning and is generally more productive. REPLs cut out the middleman -- no need to build UIs or scripts for every possible action you might want to take -- just talk to the interpreter directly.

Autocomplete plays a big role in how we use software, imagine a world where you have to type full search terms without predictions into google search, ugh, the savagery! Many developers employ this technology when writing code in order to increase their productivity. So we decided to implement this feature to help you become the power user you want to be.

In this age of containers it's much easier to run arbitrary code in the cloud. The harder parts are scaling the service, making it reliable, and —as in this case— creating cool and useful experiences. When we looked at existing Swift REPL implementations on the web we found that none delivered a stateful and interactive environment. Just an editor with a run button.