Panic, Inc., promotes Diet Coda with the tag line, "Make quick web fixes to go." However, I have found to be potentially much more useful than that in the few days I have used it. The adaptive keyboard layouts, code completion, and Bluetooth keyboard support work well for coding sessions longer than just a quick fix. Backed by reference documentation on a companion smartphone or even an Amazon Kindle, Diet Coda might tempt some developers to leave their notebooks behind.
Diet Coda can work with multiple servers. You can see the two servers I regularly work with here. Tapping the plus (+) thumbnail lets you add more servers.
Remote code editing using FTP or SFTP is configured separately from SSH terminal access to the same server. You can see the FTP/SFTP configuration screen for remote file editing here. An arbitrary file name can be assigned to identify each server. The usual information required for remote FTP access is provided in the rest of the configuration screen. Ports other than the standard TCP port 21 are supported.
The paneled window view of a remote server lets you select a file for editing ("Edit in Diet Coda"). You can also manipulate remote files and directories from this screen view.
Diet Coda's keyboard adds several keys to the visual keyboard that are very important to programmers such as Undo, indent, and left-and-right cursor movement keys. When in the mode to work with PHP code, it also displays additional keys such as "//" (line comment), ";", and "$" that are specifically useful for PHP coding. This eliminates the need to switch to the symbols plus numerals key view, which is extremely important to maintain coding rhythm. The app also provides support for storing blocks of code in clips. Several are predefined for the PHP code mode.
Important note: The green check button in the upper right of the display saves your current editing session to the remote server.
The SSH remote terminal component also has its own custom keyboard as seen in this screenshot. Diet Coda works with Bluetooth wireless keyboards, too. If you use one (see the first slide), the entire screen area is available for editing or terminal use. Note that Diet Coda is not limited for remote work with UNIX and Linux servers. Apple's Mac OS X includes an SSH server for remote access. And, there are free Open Source SSH servers that can be used with Microsoft Windows Server, too. freeSSHd is the one I use with Microsoft Windows. It has improved quite a bit since I first used it back in 2008. This could allow you to, for example, work with Microsoft PowerShell from your iPad.
We also wrote a review of Diet Coda. Click here to read it.
Finally, text clips can be defined globally, by site, and for the current language syntax.
If a recognized function is typed, Diet Coda displays the function's input variable type.