Yes, it's totally possible to write a blog, forum, or pretty much any "Web 2.0" application without using a database. You just need to be very, very careful wit

Yes, it's totally possible to write a blog, forum, or pretty much any "Web 2.0" application without using a database. You just need to be very, very careful with how you design your filesystem layout and file format. As for the file format, it would be best to stick with standard formats like JSON, XML, or YML. Or the standard serialization method for your favorite language, such as pickle() for Python and serialize() for PHP. Try not to invent a brand-new format, it's going to be error-prone and generally slower than using a standard format. A more difficult task is to maintain an index of some sort, separate from all the individual files, so that you won't have to read and parse every single file in order to generate the forum listing. Whenever a reply is posted, you'll need to bump a thread to the top of the listing. Think about how you can implement this without modifying or renaming several files at a time. And then you'll need to ask yourself how you're going to prevent inconsistencies in your data over the next few years. What if you decide to add a new field to the JSON schema and all the old files don't have that field? What if you delete a thread but an error occurs halfway through and some of the individual posts still remain? You'll need to write logic to handle such edge cases as well. SQLite solves a lot of these problems while offering the same sort of performance, if not better, on resource-constrained environments. As far as SQLite is concerned, a Raspberry Pi is a very powerful machine. There's no reason why you sholdn't be able to enjoy all the benefits of flat files together with all the benefits of a relational database.