I'm writing this post on my old Macintosh LC475, a 25MHz machine.
Unfortunately, the 68K version of iCab (the browser I'm using) doesn't render css well, and as such, most pages on Blogger are a bit jumbled. I had a tough time logging in, and had to do a little bit of cutting and pasting of URLs before Blogger would let me in. Maybe if I tried to log in via Google?
The editing page is a right mess... nothing is rendered properly, and I don't see the toolbar anywhere. So, I have absolutely NO idea how this is going to look on other systems.
But at least I can say I edited my blog, via Blogger's web interface, on my LC475.
I have experienced Web 2.0 on a 25MHz computer from 1993.