I am wondering what other software is similar to Zim-wiki? I've started using Zim at work because I like how the pages and attachments are not in a database and can be accessed straight from the filesystem.

I've started using it because I haven't been very organized with how I store files at work. I've been using Zim pages to take notes about projects and files. Since the attachments are stored in the same directory as the files it makes it very easy to find everything.

I'm curious if there are any other programs like this?