Five Hidden Gems From the Developer Folder

This post is part of a series that revisits some of our readers’ favorite articles from the past that still contain awesome and relevant information that you might find useful. This post was originally published on August 2nd, 2011.

A few weeks ago, I wrote an article about text-to-speech in OSX, and one commenter suggested I check out Repeat After Me, a text-to-speech utility hidden in the Developer folder.

While checking it out, I discovered that the Developer folder holds a stash of useful applications and utilities I’d never heard of before. I’ve found some real gems while digging through Developer Tools, including some utilities that I now use on a regular basis. Let’s go hunting for burried treasure!

Where Are We Looking?

To get these developer tools, you have to install Xcode, either from your Tiger/Leopard/Snow Leopard install disk, or for free from the Mac App Store. I had developer tools installed on Snow Leopard, and they’re still there now that I’ve upgraded to Lion.

If you’ve never checked it out before, the Developer folder can be found right inside your hard drive’s main directory. As developers will know, the applications folder inside the Developer directory is home to key tools like Xcode and Quartz Composer, but the average user would have no reason to know the folder existed.

All the applications and utilities I’ll be discussing can be found at OSX HD/Developer/Applications/.

Warning: This could get geeky.

Repeat After Me


This utility is a very powerful, complex text-to-speech tool, which can be used to alter text-to-speach output and export your spoken text to .aiff. Repeat After Me allows you compare recorded audio (like your own voice) to the automatically generated speach, and impose pitches and durations from the recorded voice onto the text-to-speach output. It’s a complicated—but powerful—process, though practical applications are hard to think of.

While I was searching for information about Repeat After Me, I did come accross one interesting application: creating digital “singers” to be used in GarageBand compositions. You could theoretically “train” the computer to sing a line of text, though in practice this might be pretty time consuming.

Pretty cool, whatever it is

Pretty cool, whatever it is

Core Image Fun House

Developer/Applications/Graphics Tools

Your Mac comes with powerful image processing technology called CoreImage, which powers many third-party image editing apps. If you don’t feel the need to download (or pay for) a pretty face for technology you already have, you can achieve some pretty cool effects using the Core Image Fun House.

Core Image effects are non-destructive, so you can add layers of effects to the “Effect Stack”, then modify or delete them. There are dozens of effects to play with, from common adjustments like hue and saturation, to powerful Photoshop-like effects including displacement distortion (similar to Photoshop’s displacement map feature).

If you look closely, this image is being distorted by a picture of a flower

If you look closely, this image is being distorted by a picture of a flower

Core Image Funhouse is meant to familiarize software developers with the tools available to them, but that doesn’t mean the rest of us can’t have a little fun!


Developer/Applications/Graphics Tools

Pixie is a really useful little utility that magnifies anything on your screen up to 1200%. This feature is really handy for taking a close look at UI elements in both desktop and web applications without having to open an image editor, which can be very useful for designers.

On closer inspection, I still don’t know what they were thinking

On closer inspection, I still don’t know what they were thinking

AU Lab


AU Lab is a fully-featured audio mixer, and though I don’t know much about the subject, I’ve read some really positive comments about it in forums. It’s been compared to RAX in terms of functionality, and is very lightweight and fast. I’ve read that it has a pretty steep learning curve, but it comes with extensive help documentation, and you can’t beat the price.

It may not be pretty, but it is powerful

It may not be pretty, but it is powerful



FileMerge is probably my favorite of the Developer Tools, I’ve actually used it a couple times to compare documents. FileMerge works like a stripped down version of Kaleidoscope, it “spots the differences” between two text documents.

This kind of utility is useful for both coders and for people that work in writing or editing: it could spot the crucial difference that broke your web app, or show you what changes your editor made to an article. When I do editing work, I usually use Word’s “compare documents” feature, which is good for when you really need to see how something was changed, but something like FileMerge is ideal for getting a general idea of what’s different.

You can drag and drop files into FileMerge to compare them

You can drag and drop files into FileMerge to compare them


There are dozens of applications and utilities in the Developer folder, but most of them are only useful to software developers. However, even if you’re not a developer, it turns out there are still some very useful, freely available tools to be found. I don’t think any of these applications would find their way to my dock, but I call up Pixie and FileMerge from time to time, and I’d definitely play around with Core Image Funhouse if I wasn’t already such a Photoshop nerd.

I’d be curious to know how many Appstorm readers have Developer Tools installed, whether or not you actually develop software. Have you tried out any of these tools? Are there any other little-known apps I’ve missed?


Add Yours
  • About Repeat After Me – it’s in the Devs folder for god sakes, what about its purpose being debugging the voice files that come with OS X or that you can even create yourself?

  • I was reading the first couple of lines of this article and promptly fired up the Appstore.

    Somehow Apple decided to offer XCode for free now ? I thought it was 4 or 5 bucks before ? Did i miss something ?

    • Just like with wifi and FaceTime Apple is forced to do so. It is a major upgrade for a functionality which did not exist in first place, but it will be free in a upcoming version of the OS.

      Head here for more information about it:

      • I’m aware of the accounting bit of FaceTime, didn’t know it also applied to XCode. Anyhow, i downloaded XCode minutes ago.

      • XCode was always free, it’s the latest developer version they were selling in the App Store, that’s why it cost.

    • Yep, not sure when that happened.

  • I would actually say Kaleidoscope is more of a stripped down version of FileMerge in terms of functionality. Kaleidoscope might be a pretty tool for comparing, and it definitely has its advantages (comparing images etc) but it lacks most features FileMerge does not show in first place. These includes complex comparing of folders and their structures and contents, but most of it, it is able to choose the parts from each side you want to keep and merge them together into one document. This is why it is called FileMerge, it is a merging utility mostly used for tools like svn, git or hg.

    • I came here to say precisely the same thing! I wish they’d add merging to kaleidoscope.

    • I would have to agree. Whilst I really like Kaleidoscope it lacks the basics that are essential. Shame really. When I purchased it I was hoping they would have added at least merging but alas :(

  • Repeat After Me isn’t that complicated:

    1. Type something to the text field (like *push me. and then just touch me. till i can get my. satisfaction*)
    2. *Build Graph*
    3. *Record* (press the record button in the dialog, say the typed phrase)
    4. *Impose Recorded Durations*
    5. *Extract Pitch*, *Impose Pitch* (optional)
    6. Focus the graph, and select *Sound – Speak*

    (The voice used is *Speech.prefPane → Text to Speech → System Voice*.)

    Utilities/Accessibility useful for finding UI element hierarchies for AppleScripts.

    You can customize shortcuts by editing MainMenu.nibs with Interface

    Utilities/Icon for creating icns and ico files. for example the *Activity Monitor* template can be used to record the average CPU and memory use of processes over time.

  • Quartz Composer is definitely the most interesting Developer Tool to me. It’s just sad that there aren’t that much tutorials online.

  • Yeay, I helped get an app noticed on appstorm :)

  • Thanks for excellent tutorial, however I cannot find the developer folder “just inside” the OSX HD. I can find a developer folder under /library7developer, but in this folder I find nothing of relevance to this article. Could the reason be that this machines was completely “reformatted” for Lion so there will be no “leftovers” from SnowL ?

    • These tools may no longer installed by default with Xcode . To download them just go to the Xcode menu, Open Developer Tool, More Developer Tools.. and you will then be taken to a page on the Apple Developer Portal where you can download them.

  • I wrote a suspiciously similar article to this for MacApper back in 2007 called “The Gems of Apple’s Development Tools”.


    • I don’t think they’re “suspiciously” similar at all.

      Anyone can write about these developer tools, can they?

  • I was wondering if you can get the same iSpeech service that I use for iOS on OSX?

    The voices are better imo than the ones that come from Nuance.

  • A second vote here to add Icon Composer to this list.

  • I have used Core Image Fun House as an easy tool to modify images for use on websites. It is pretty cool.