What are the other IDEs for Arduino?

There is an Arduino Eclipse plugin named sloeber! And Eclipse is an awesome cross-platform open-source IDE!

Stino is good. It requires Sublime Text 2 which has an indefinite free trial.

Visual Micro provides a full build system with debugger for Arduino in Microsoft Visual Studio. For advanced users it also allows the underlying Arduino source code to be viewed or modified, enabled projects and/or libraries to be edited from any location and shared in multiple projects alongside true cross-platform intellisense.

For more go to The Official Arduino Site

For development on Windows, there is a special edition from Arduino official IDE called arduino-erw, This edition much better the last one because it fixed a lot of lagging and stability issues!

Expanding on Fake Name's answer, there is also Visual Micro's Arduino plugin for Atmel Studio (built off Visual Studio). It shares the tools, sources and libraries with the Arduino IDE but provides all the code completion and other features of Visual Studio.

The Visual Micro plugin also works in all versions of Visual Studio. Provides Arduino usb debugging and an Arduino IDE compatible Board Manager.

vim can be used for Arduino development, but it will take some configuration (as is the way of vim). You'll need the syntax file and this plugin that enables you to compile and deploy from vim.

Grant Lucas produced a great write-up on getting your environment situation squared away:

Using Vim for Arduino development

Here's a quick post on setting up Vim for Arduino development instead of using the Arduino IDE. If you're a heavy Vim user, it can be a bit of a shock to go into a different editor. Thankfully the setup is pretty easy to get this all working with Vim. This post is assuming you are comfortable with how Vim is setup and ideally already have an environment that works for you.

Install the Arduino IDE

Wait. What?!? I hear you say. I know, I know. We're not actually using the Arduino IDE but we need it for some configuration and the files it installs. The Vim plugin we'll be using ties into what the IDE installs and configures so it's needed. You can download the IDE from the Arduino site.

Install vim-arduino plugin

To get the main goodness of compiling, monitoring and deploying to an Arduino, grab the latest version of vim-arduino. Install it in your .vim folder using what ever method you use to manage your Vim plugins. Hint: I'd recommend Pathogen as it makes installing as simple as dropping the plugin folder into a bundle folder.

Vim syntax file

Next up is to get the syntax file so we can have nice colour coding for .pde and .ino files. Download the latest arduino.vim and install it in your Vim syntax folder. To get the syntax to apply to the correct file types add the following to your vimrc file

au BufRead,BufNewFile *.pde set filetype=arduino
au BufRead,BufNewFile *.ino set filetype=arduino

Configuring the Arduino IDE

Before trying to compile and deploy with Vim, get it all working with the Arduino IDE first as the Vim plugin just calls from the settings saved by the IDE. If it's working in the IDE, it should work in Vim. Make sure you select the right tty.usbmodem* serial port from Tools > Serial Port in the IDE. Note: This will only show when the Arduino is plugged in.

Working from Vim

Once you can communicate with your Arduino from the IDE you should be fully good to go with Vim. You shouldn't have to open the IDE unless you want some example code. Open up your sketch file in Vim and use <Leader>ac to compile a sketch, <Leader>ad to compile and then deploy to the connected Arduino and <Leader>as to open a new window with screen to monitor the serial output from the Arduino.