First I am silent for exactly 3 months, now 2 blog posts in two days. But I can make the interesting announcement I promised yesterday.

During the summer I created a new website for the Stacks project (my announcement, official announcement). At that moment we've toyed with the idea of making a full-fledged online view, but the lack of a good xypic parser made this impossible. And what would the Stacks project be without commutative diagrams? At that point XyJax was already around, but it was incapable of rendering commutative diagrams, and it was inactive. Yet a few months ago it became active again, and after a request the developer implemented commutative diagrams (thank you!).

Now every tag has by default the online view of a tag (code view is still available if you want). A tag's TeX code is processed in PHP to get something that approximates the pdf, after which MathJax and XyJax are let loose to render all math. Besides that, everything is tightly linked together so if you're viewing a section's tag (e.g. stacks:tag/06U0) you can:

• click on numbered theorems to go to their specific tag page;
• use all cross-references between tags;
• jump back and forth between sections.

So point your browser to the browse page, pick your favourite chapter and section, and you can start reading the Stacks project without opening any pdf's, just by clicking around through the entire project. Don't forget there is a powerful search functionality too.

If you encounter any bugs, please contact me. I am aware that it isn't working properly in Opera at the moment.