Provide a detailed summary of the following web content, including what type of content it is (e.g. news article, essay, technical report, blog post, product documentation, content marketing, etc). If the content looks like an error message, respond 'content unavailable'. If there is anything controversial please highlight the controversy. If there is something surprising, unique, or clever, please highlight that as well:
Title: Show HN: SQRL – Anti-spam rules language Twitter acquired in 2018, open-sourced
Site: websqrl.vercel.app
SQRL was the language designed by Smyte, and later acquired by Twitter in 2018. It is a safe, stateful language for event streams, designed to make it easy to enforce anti-abuse rules. This demonstration is running on the Twitter  1% sampled stream , and include some basic example rules. To see the tweets live on twitter.com follow the timestamp link. These are not recommended for use in production, but are rather examples of what can be achieved easily with the language. We also have a demonstration running on the  Wikipedia event stream . For more information see  the website , or  the motivation .