Broadband Optimizer v1.5
Enigmarelle Development
http://www.enigmarelle.com/

Like most operating systems, MacOS X doesn't come out of the box to take full advantage of a high-speed, broadband internet connection. Luckily, because of its Unix base, there's an easy fix for that. By making certain tweaks to your network settings, you may be able to almost double your download speeds.

Broadband Optimizer works by increasing the memory buffers used for TCP transfers, so that data comes in bigger chunks at at time - Man-sized broadband chunks, not modem-sized kiddie chunks.

With this version I'm asking for purely voluntary donations. While looking at the VersionTracker download page (56,991 downloads as of this writing) the inevitable thought crossed my mind - "if I had a dollar..." So I'm yielding to temptation - if you have a few spare bucks you can donate whatever you think is appropriate by visiting http://order.kagi.com/?UR8 and making a donation there by filling out the amount in the form field. The suggested donation is US$5, and the minimum allowed by Kagi is US$2.50.

Automatic Installation:
Double-click on the BroadbandOptimizer.pkg file in this folder. The Mac OS X Installer program will open and prompt you through the installation process.

Manual Installation:
If you'd rather do things yourself, I can understand that. See the Read Me file inside the Manual Installation folder.

Whichever way you install BroadbandOptimizer, it is recommended that you run Disk Utility's repair permissions function on your startup disk after installing.

To verify that the changes are in effect, open Terminal and type sysctl -a (that's a letter L on the end, not a number 1.) The listing should contain the following lines:

Enjoy your newfound speed :) You may want to further tweak your settings for your particular connection by opening the file named BroadbandOptimizer inside the folder you just installed in any text editor (BBEdit, vi, or our own TideText work well. If you use TextEdit make sure you're saving the file in plain text mode, not RTF. If you're using another text editor, make sure you're saving with UNIX line endings.) Change the numbers above to a slightly lower amount (they're already set as high as is likely to make any improvement.) The OSX default is 32768, so that's the lower limit that makes any sense. Try 49152 to start with.

While you're trying out new settings there's no need to edit the script and restart after each change - open Terminal and type sudo sysctl -w net.inet.tcp.sendspace=49152 (or whatever setting you're experimenting with) then hit Return. This has the same effect as running BBO. Broadband Optimizer merely automates the process so you don't have to type it in after each login.

Uninstalling:
If you decide you don't want to keep BroadbandOptimizer, just move the BroadbandOptimizer folder at /Library/StartupItems to the trash and restart.

Disclaimer:
I make no guarantees express or implied about anything whatsoever. BroadbandOptimizer might or might not work for you, depending on your connection. It might slow things down. It works fine for me here. YMMV.

Version History:
1.5 - Added Installer package. Fixed Panther system log error on startup.
1.0 - Removed a network check that turned out to be unnecessary - BBO should now work on PPPoE-based DSL connections without modification - and also cleaned up the code a bit. ( thanks Guillaume :)