Bonjour is a great service that runs in the background of your Mac to auto-discover network resources, that is, it’s great until mDNSResponder goes haywire. I was recently in a very creatively crafted network environment that made Bonjour absolutely freak out and tax my CPU with a million processes, so I opted to just disable the service temporarily. Generally speaking you should leave Bonjour enabled since it’s functionality is ubiquitously used throughout Mac OS X, but if you DO want to disable mDNSResponder, here’s how to do it:

Turn off mDNSResponder by disabling Bonjour

Launch the terminal and type:
sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

Turn on Bonjour aka mDNSResponder

To reenable Bonjour simply type the following to reload the mDNSResponder daemon:
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

Both of these commands to enable or disable Bonjour will require your administrator password to execute as root, hence the use of sudo.

mdworker is short for ‘metadata server worker’ and if you’re still confused don’t feel bad. mdworker is basically the core technology behind Mac OS X’s awesome search engine Spotlight, it spiders meta data from your Mac and its files and creates a readable index so that you can find things practically instantaneously via Spotlight (command-spacebar). Here are some common questions and answers regarding mdworker, inspired by my recent switcher friend Daryl, who tweeted me asking why mdworker is taking up so much CPU.

What is mdworker?

As mentioned above, mdworker is part of Spotlight, which is basically a search engine for your Mac (think Google but locally, for your own files).

mdworker is slowing down my Mac with 60% CPU usage!

Yes, mdworker will sometimes cause your Mac to be slow and have high CPU usage, this is totally normal. You should just let it run until it’s finished, and CPU usage will be back to normal.

How long does mdworker take to finish?

This is entirely dependent on the last time that your Mac filesystem was indexed and the amount of new files since indexing. If you just plugged in a loaded external hard drive, expect it to take a while. 15 minutes to well over an hour are not uncommon amounts of time for mdworker to run.

Should I kill mdworker? What happens if I kill mdworker?

No you shouldn’t kill mdworker, because it’s doing you a service by indexing your Macs contents. If you do kill mdworker, your Mac filesystem will not be completely indexed and it’s searchability will be greatly reduced until mdworker runs again and completes a full indexing. There is no serious problem with killing mdworker, it’s just not recommended.

How can I stop mdworker or disable mdworker?

Since mdworker is part of Spotlight, you’ll have to disable Spotlight to disable mdworker. Again, this is not recommended, but if you want to disable mdworker here’s a how-to guide:
How to Disable Spotlight

What about mds? Is this tied to mdworker?

Yes, mds is the parent metadata server that runs the child process mdworker, the two usually run concurrently. You can read specifically about mds and Mac OS for more information.

Squid is a web caching proxy that is wildly useful for those of us on slower internet connections or anyone that has reduced bandwidth availability, it reduces bandwidth by caching and reusing frequently accessed web pages and works with http and https. Squid has been particularly useful to me on business visits to places where broadband is a distant concept rather than the norm, it really makes the web usable in challengingly slow internet environments. Squid Manager is a nifty manager to use the Squid web caching proxy on your Mac, so if you’re in the market to use Squid on your Mac, be sure to check out Squid Manager.

Download Squid Manager now
Developer home

Every once in a while you stumble upon a utility, app, or feature that you immediately fall in love with and wonder how you ever live without… well today and for me, that is iStat Menu. It’s been around a while, but apparently I’ve neglected it to my own detriment because this thing is awesome. Installing is a breeze and it becomes a System Preference pane, where you can adjust settings to monitor everything from the temperatures in your Mac, to CPU activity, disk space, bandwidth usage, and oh so much more. If you ask me, this is an absolute must download for Mac geeks, so check it out!

Update: Someone purchased the rights to the software and started charging, but you can still download the free version of iStats Menu and get all the features.

You can create an instant quick and dirty stopwatch via the Mac OS X command line by launching Terminal and typing: time cat , then hit enter and the stopwatch begins, you can stop the count by hitting Control-C, which will return something back that looks like this:

$ time cat
^C
real 0m5.905s
user 0m0.001s
sys 0m0.003s


The top ‘real’ number is the time that passed since executing the command. How this stopwatch works is you are using the ‘time’ command to time how long another command takes to execute, but since cat requires something to output and we are not providing any, cat does nothing, creating a simple stopwatch.

Need a PDF Editor for Mac? I did too, and this is what I learned. Adobe Acrobat Pro is great software with some killer features, but it’s expensive. Acrobat is hard to beat in it’s functionality, but if all you’re looking to do is make small changes and edits to PDF files, spending $350 for a PDF Editor might be a bit overkill. So what are some other options for a Mac PDF Editor?

Best Free PDF editor for Mac

Preview – FREE – included in every Mac OS X install, the most recent version of Preview in Snow Leopard lets you make all sorts of annotations to PDF documents. In the Snow Leopard version, you can draw shapes onto PDF’s, and write text directly to PDF files for things like a digital signature. It’s basically a limited PDF editor, for free, and there’s no download required! If you’re looking for a free PDF editor solution, I highly recommend just using Preview.app that is already included in Snow Leopard!

Other Free PDF Editors for Mac

Skim – FREE – we’ve written about Skim before, and it works pretty well for making quick notes to PDF documents.

Scribus – FREE – an open source desktop publishing app that has limited PDF editing abilities, and the ability to create your own PDF’s

Best Paid Solution for Editing a PDF on Mac

I say this is a tie because PDFPen is great but a lot more limited than Acrobat, but if you’re just looking to make simple changes, save yourself $300 and buy PDFPen. If you’re a professional and you are going for advanced PDF editing and production features, get Acrobat, it’s expensive but there’s a reason: it’s extremely powerful.

PDFPen -$49.95 – a whole lot cheaper than Adobe Acrobat, with much of the same functionality in terms of making quick text edits to PDF files and the ability to edit faxes, OCR files, and more.

Adobe Acrobat Professional 9 – $350 – the grand daddy of all PDF editors, you’ll pay a fortune for it, but if you’re really serious about creating, editing, and modifying PDF’s this is the best way to go. There is an upcoming version X (10) too that will have even more powerful features.

If you’ve looking for the location of your iPhone Backup files, then look no further. Whether you use Mac OS X or Windows, the iPhone backup process is basically the same, iTunes backs up all of your iPhone files and identifier information to a specific directory in the following locations… but first a warning: if you don’t know what you’re doing, do not mess with these iPhone backup files! Ok on with the backup locations:

iPhone Backup Location for Mac OS X

in Mac OS X your iPhone files are backed up at the following location:

~/Library/Application Support/MobileSync/Backup/

The (~) symbol signifies your home directory, which is the same place all your other personal documents are stored.

iPhone Backup Location for Windows 7, XP, and Vista

Windows XP stores all of your iPhone backup files in this location:

C:\Documents and Settings\user\Application Data\Apple Computer\MobileSync\Backup

Windows Vista and Windows 7 backs up the iPhone files to here:

C:\Users\user\AppData\Roaming\Apple Computer\MobileSync\Backup

Obviously if your main drive is not C: then you’ll have to change that, same goes for ‘user’

Note to Windows users: the Application Data and AppData directories and their contents (iPhone backups included) are considered ‘hidden’ so you will need to enable ‘Show hidden files’ within Windows Explorer before you will be able to see the files.

iPhone Backup notes
There’s various reasons you’d need (or want) access to the iPhone Backup files, but generally speaking you should be able to rely on iTunes to handle all your iPhone restoration and backup needs. If you’re interested in keeping your own backup copies though, say for Jailbreaking purposes, knowing the location of the iPhone backup is handy.

You’ll notice that the files in the directory are almost all unusual and randomized names, like ffb541c48e97051fff2b1f906577cbef71123c4fb.mdbackup, these are all automatically generated. There’s also a few xml files in the directory that have unique identifier information about your iPhone.

This probably goes without saying, but unless you know what you’re doing you should NOT edit any of these iPhone backup files! Editing or deleting any of these files could result in improper, malformed, or otherwise unreliable backups, and any other number of problems with your iPhone.

If you’re looking for a way to access your iPhone files through some kind of browser application rather than the Finder or Windows Explorer, you could try some of the apps out there, but many of them are poorly made in my experience.

[ This article was confirmed accurate and updated on June 22, 2010 ]

Burning an ISO in Mac OS X is very easy thanks to the built in Disk Utility application that is included from Apple on every Mac, meaning it’s free! Here’s how to use Disk Utility to Burn an ISO image on your Mac.

Burn ISO in Mac OS X

* Open Disk Utility, it’s located in /Applications/Utilities
* Pull down the File menu and select ‘Open Disk Image’
* Navigate to the ISO image file that you want burned and click “OK”
* Insert a Blank Disk (CD or DVD, depending on ISO file size)
* Click ‘Burn’

That’s it for Disk Utility! This works in Mac OS X Leopard, Snow Leopard, Tiger, and every other version of Mac OS X that I have ever used. Have a DMG file? You can burn those too, or you can convert DMG to ISO easily.

The new version of the Remote app for iPhone [iTunes link] has a great social feature that allows party guests with the app installed to connect to iTunes shares, see what’s currently playing, add songs to playlists, vote on songs to be played, and make requests.

As the linked posterous blog states: “This is the future of the juke box. The democratization of music wherever you are.”

How cool is this for iPhone party goers? It’s only a matter of time before this makes its way into bars, lounges, and nightclubs.

Check out more here: Sachin@Posterous: At your next party, use iTunes DJ to let *your guests* pick what music is played and vote on the next song

[iPhone image borrowed from above posterous link, it's not my Britney Spears playlist, I swear]

iTunesHelper or iTunes Helper, is a program from Apple that runs in the background and monitors for the connection of any iPod or iPhone to the computer, if an iPod or iPhone is detected it will automatically launch the iTunes application. The functionality is the same on both Mac OS X and Windows PC’s, and there is no serious ramification to disabling it (other than that iTunes will no longer auto-launch upon connecting your iPhone or iPod).

Disable iTunes Helper in Mac OS X

iTunesHelper.app is autoloaded during system boot in Mac OS X, but if you’re having problems with the iTunesHelper app you can easily disable this from auto-loading by going to System Preferences -> Users -> Login Items, clicking on the iTunesHelper application and then clicking on the minus (-) button at the bottom of the list (thanks Gord!). Unselecting the checkbox next to iTunesHelper application hides it during system launch, as seen in this screenshot:

Disable iTunes Helper in Windows

Go to Start Menu -> Run, type in ‘msconfig.exe’ and hit enter. A system configuration utility will pop up and click the “Startup” tab, from there navigate to iTunesHelper.exe and disable it by unselecting the checkbox next to the app name.

Why you would want to disable iTunes Helper

Sometimes iTunesHelper freaks out and causes system hangs, CPU drain, and other frustrating problems. Otherwise, you may just not want iTunes to automatically launch if you connect an iPod or iPhone, you can disable that setting within the iTunes settings, or you can disable iTunesHelper itself. My cousin was recently having all sorts of problems with the actual iTunesHelper daemon running in the background, so I helped him disable it completely, and his problems were resolved.