Proxifier like software on Unix

The first place to look is your distribution's package list. That's where you'll find the easiest-to-install programs. Some package management tools provide advanced ways of searching it.

• On Debian and Debian-based distributions (e.g. Ubuntu), you can search package descriptions with apt-cache search or aptitude search (on the command line), or through the search facility in interactive package managers such as Aptitude and Synaptic. There's also more structured information in the form of tags: install the debtags package, and make basic queries with the debtags command or browse the tag database in Aptitude. Tags are a good way to find packages to work with a particular file format, for example.

• On Red Hat and other distributions using yum (e.g. CentOS, Fedora), you can search package descriptions with yum search (on the command line).

If the package is not in your distribution, it might be available from an unofficial source. Try the Linux packages search, which indexes several official and unofficial sources of Linux packages. For Ubuntu, search for the package in a PPA.

If your distribution doesn't have anything, you can also look in the package database of another distribution. Example distributions with a large package database are Debian, Fedora, FreeBSD, Ubuntu.

NVpy is "a cross-platform simplenote-syncing note-taking app inspired by Notational Velocity."

Looking at screenshots NVpy looks like a closer match than TomBoy.

Here's a little write-up of NVpy on Lifehacker.

Though this guy didn't like it and tweaked gvim a bit instead.

Looking more, I found NVVim which "is a clone of the mac app Notational Velocity in vim. It is designed for fast plain-text note-taking and retrieval."