Here is a short list of Joomla! extensions and desktop software I use in my development process. While each project I do has unique needs and extensions, all of the tools listed here are fairly standard and indespensible in my Joomla! workflow.
Mandatory Joomla! utilities from Akeeba:
It's hard to imagine using Joomla! without Akeeba Backup, it's use is so universal it almost doesn't need mentioning. I use it not only for backups, but also for building and saving preconfigured installations, quickly moving sites from local and developent servers to live servers and back again. The time it has saved me can't even be measured, it's huge. If you're not using it yet, you should be.
Maybe not as well known as Akeeba Backup, Admin Tools is every bit as useful in a different way. It offers a number of quick and helpful features relating to security and maintenance. I came across this extension when I was using J1.5, security was a bit of an issue back then, Admin Tools was the answer for deterring some very persistent hackers that had targeted one of my clients. While Joomla! exploits aren't as big of an issue as they used to be, the simple security tools add another level of protection. The file permissions and database functions alone are huge time savers if you find yourself in a situation where those factors become an issue. Great for all around troubleshooting and maintenance.
While Akeeba makes a suite of fantasitic products, these two get installed on every site I work with. There are free versions that work great, there is also the option for paid subscriptions which offer more features and support.
Joomla! Template development tools developed by Rocket Theme and all are free
+ very flexible template framework system with tons of features, allows me to work quickly and covers all of my frontend and backend template development needs.
+ available for Joomla! and WordPress
+ IDE Style Joomla! text / code editor. Can't live without it.
+ Fancy and flexible article display with a number of modes (rotator / tabs / mosaic etc)
+ has a basic CCK (simple mode) for creating slides and content on the fly
A simple IDE that offers an assortment of tools, I think of it as my development utility knife. The individual features (code editor, FTP, SSH, SVN etc) may not be as powerful as some stand-alone counterparts, but I appreciate the simplicity of having everything I need inside one of application that has a single window interface. At $99, it's a good option for first time IDE shoppers or anyone looking for a simple all-in-one solution.
As mentioned above, Coda has FTP, but Transmit is a much more powerful stand-alone FTP application. It comes in handy for large transfers, managing files for multiple sites and having it along side coda helps me with multitasking. It can be used in conjunction with virtually any code editor or application.
An extremely powerful stand-alone code / text editor. It can perform virtually any code writing or editing task imaginable and it can be customized, extended and controlled in a ridiculous number of ways. The complexity is deep, but it also comes with a learning curve. Once I figured it out, got my preferences set and integrated it into my work flow it became indespensible. I find the search and multi-cursor features to be particularly useful in many situations.
Araxis Merge is a file comparison tool, which is useful in many situations. As template developers, we may need to update files that contain custom changes on occasion. Some examples might be: fixing template overrides files that have broken after a Joomla! update, or upgrading third party template files to a new version. Simply overwriting a file also overwrites any customizations you have made in that file, file comparison allows you to review and merge the differences between the files into one file. Araxis Merge is powerful but a bit pricey, there are plenty of lower cost alternatives on the market if budget is a concern.
Also a bit pricey ($30 to $50 monthly with a one year minimum), but money well spent in my opinion. Having access to the most recent versions of the standard Adobe applications ensures that I can handle any graphics or web files that my clients might throw at me, as well as perform my own work without restrictions. There are an assortment of utilities included, as well as 20gb of cloud storage with sharing features, but that's just icing on the cake.
MAMP (My Apache – MySQL – PHP) allows you to create a local server environment on your computer, it has everything you need to run Joomla! and other database driven web platforms. While I do have a development server online, having a local server environment is essential for testing, developing and troubleshooting. It also comes in handy if you need to keep working despite having no internet, server issues, or perhaps traveling somewhere (like Mexico for example) where internet service isn't that great. MAMP PRO can also be used to host live websites and much more using your computer as the server. MAMP is free, MAMP PRO is around $60.
Desktop Tools (for Apple OS X, some are available on PC )