It's simple and nearly fail-safe. If it comes into trouble, it stops with a tiny message. Excellent tool for all comma fetishists.
A real time-saver for people who make minor Wikipedia edits. Once you've selected some text in a Wikipedia article, just press Ctrl+E (Windows, Linux) or Command+E (Mac) and a small editor window appears with that text. Make your edit, click OK, and your change immediately appears in the article. Great!
Note: In the extension's Options, the (changeable) key combination appears as "accel-e". The developer explains why, below.
This is to make it platform-neutral. Windows and Linux have a control-key, Mac has an command-key. accel is for using control or command key, whichever exists on the computer.
Don't ask me why it's named like this, it is named like this by Mozilla in the API.