On this day, ten years ago, MathB.in was released on the world wide web. MathB.in is a web-based mathematics pastebin service that is used for sharing snippets of mathematical text with others. The source code is available at github.com/susam/mathb.

## A Brief History of Mathematics Pastebins

MathB.in is the oldest mathematics pastebin that is still alive and serving its community of users. It isn't the first mathematics pastebin though. It's the second. The first one was written by Mark A. Stratman and hosted at mathbin.net until 2020. It was very popular in the `#math` and `#physics` channels on IRC networks between 2006 and 2013. It did not have live preview but it used an actual LaTeX system in the backend for rendering mathematical formulas into images, so the output was of pretty good quality. It served IRC users very well for sharing problems and solutions quickly with each other on IRC channels. Since late-2014, Mark's website began intermittently displaying a notice that the website was shutting down. The notice replaced the actual pastebin on some days, so users were forced to look for alternatives. MathB.in was already available on the web and popular among IRC users by then, so it turned out to be a good alternative. Mark's website disappeared sometime in late-2020.

Another alternative to the first mathematics pastebin was Huy Nguyen's texpaste.com. It was released on the web in September 2013. I believe it was the third mathematics pastebin to be released on the web. In fact, it was a bit more than a pastebin. It allowed users to sign up for accounts and save their notes in their accounts. It had some nifty widgets to click and automatically insert common LaTeX symbols instead of typing them out manually. It had its own community of users. However, it suffered from serious spam problems. Searching for "texpaste.com" on Twitter shows how the service was being exploited by spammers to share dubious content and links several times every single day between December 2016 and February 2018. Despite the spam problems, it continued to serve its genuine users for many years. Finally, the website disappeared in 2021 and has not returned since then.

## The Story of MathB.in

MathB.in was born on Sunday, 25 March 2012, after a single night of furious coding. The previous night, I happened to stumble upon math.stackexchange.com and I noticed that it seemed to have decent LaTeX support. As I dove deeper into the HTML source code of the pages of this website, I was surprised to see that the rendered LaTeX was not made of image files embedded into the web pages which used to be a prevalent practice in those days. Instead, the mathematical formulas were rendered as text with sophisticated styling done with CSS to make the rendered mathematics formula look as good as a PDF rendered by an actual LaTeX system. On further investigation I realised that this Stack Exchange website was using MathJax to produce high-quality typography from LaTeX code. As a frequent participant in the `#math` channels on various IRC networks, I immediately realised that using MathJax could lead to a modern mathematics pastebin with live preview and beautiful mathematics rendering right within the web browser without requiring a LaTeX system in the backend.

Thanks to that chance encounter with MathJax, I spent the rest of the Saturday night coding a new mathematics pastebin using MathJax and PHP. After coding all through the night, registering a new domain name and setting up a website, MathB.in was published early Sunday morning. I shared the link to the website with some of my friends who were fond of sharing mathematics puzzles and solutions. I also announced its availability on the MathJax mailing list. Since then word about my new website spread to various IRC communities and it soon became quite popular in mathematically-oriented channels.

## Source Code

The source code of MathB.in was originally written in PHP. I gradually began releasing its source code part by part in November 2013. The first complete open source release of MathB.in was done in December 2013.

The early source code of MathB.in was quite complicated and over-engineered. I was young and naive. Much like how toddlers and young kids like to play with miniature forms of real world objects like cars, trains, trucks and kitchen sets, in my naivety, I had ended up creating a miniature form of the multiple levels of abstractions and complexity we see in the corporate world of software engineering.

The thought of rewriting the software and simplifying it crossed my mind many times. Incidentally, several years before writing MathB.in, I had stumbled upon the Lisp family of languages. It was during a long layover at an airport in September 2007 that I decided to boot my laptop running Debian GNU/Linux 4.0 (Etch) and learn some Lisp programming. I happened to have GNU CLISP 2.41 installed on it, so I fired it up and began learning Common Lisp. A few months later I also dabbled in Scheme. I found the sheer simplicity, beauty and elegance of Lisp and Scheme to be fascinating. But the thought of writing websites using Common Lisp did not occur to me until much later.

At some point much later, I began rewriting MathB.in in Common Lisp while preserving its user interface and most of its behaviour. MathB.in no longer runs on PHP. It has been rewritten in Common Lisp and the entire application code is now a single Lisp source code file.

## MathB.in Today

While the user interface and behaviour of MathB.in has remained largely the same as it was on its first day of release back in 2012, there have been some new additions to its feature set. Support for GitHub Flavoured Markdown (GFM) has been added by popular demand. It now uses the TeXMe renderer to more robustly parse a mix of Markdown and LaTeX. A dark colour scheme has been added which is displayed on web browsers that are running on a desktop with dark colour scheme enabled. The layout of the user interface elements are now responsive and adapt to small screen devices.

Today MathB.in is used in various IRC channels for exchanging mathematics problems and solutions. From the testimonials I have received so far, I know that it is also used by many teachers in schools and colleges to hand out problems, sample solutions and notes to their students. Occasionally I receive emails and messages from kind strangers on the Internet who tell me how useful MathB.in has been for them. Running this project for a decade and knowing that it has been useful to many people has brought me joy.

Update on 16 Mar 2025: After about 13 years of continuous service, MathB.in has been shut down today. See the post MathB.in Is Shutting Down for more details about this.