End of support for OS X 10.4 and 10.5

As the publisher of Low End Mac and a daily user of Dropbox on production Macs running OS X 10.4, 10.5, 10.6, and 10.9, I depend on Dropbox to automatically keep work files synced between several different Macs. Using the Web interface is not a practical option when you are updating dozens or hundreds of files daily.

I want to know why Dropbox is dropping support for older Macs that remain in productive use. Is Dropbox making some technical change on May 18 that OS X Tiger and Leopard cannot support? Is Dropbox changing its code base to a development environment that no longer supports OS X 10.4 and 10.5? Or is Dropbox simply pulling the plug on a minority platform?

At lowendmac.com, 12.5% of Mac users visiting the site are using Mac running OS X 10.5 or earlier to do so. This represents tens of thousands of Mac users, most of them on PowerPC hardware that cannot run OS X 10.6, many of them also using Dropbox on newer Macs that run 10.6 and later, and a few only using PPC Macs. In most cases, we have chosen Dropbox because it is compatible across platforms while competing products have left our older hardware behind.

Please explain the rationale behind this decision - and whether there might be some way to continue Dropbox support on our aging - yet still very useful - hardware.

Thank you!

Dan Knight, publisher, LowEndMac.com