Remark.ing is a microblogging site that aggregates markwhen[0] documents. A markwhen document is just a collection of dated entries in a single file. So, with remarking, each of those dated entries gets its own "post" that has its own url and comments and whatnot. It's like handwriting RSS. And your home feed is a chronologically sorted list of those entries from different documents. That's it!
Remarking has its own UI for posting and writing but is backed by the documents you choose to upload/share in meridiem[1]. So you can still use meridiem to add stuff in the future, edit previous posts, etc.
The motivation here is really that microblogging sites need not be anything more than interweaved journals, which is what this is. You can backfill experiences that you want to remember, schedule posts in the future, all with a single text file.
[0] markwhen.com [1] meridiem.markwhen.com