Luckily, there is a site which still has available the versions of the Qt SDK that supported Fremantle:

ftp://ftp.informatik.hu-berlin.de/pu...l.no/QT/qtsdk/

(And thank you for reminding me, I wanted to pull down the Linux version of the SDK myself; I'm setting up a couple of new Linux boxes.)

There are a number of versions available at that site; you'll need to select which platform you want to run on (Linux, Mac, or Windows); you'll also want to select the "offline" version of the installer, as the "online" installers depend on the Nokia servers that are gone. Also, version 1.1.2 was the last version with explicit support for Fremantle, so it's probably best to choose that one.

After installing the SDK, you'll still need to open the Qt Package Manager and pull down the Maemo toolchain. (Hopefully, that is still available as well.)

After that, you should have all you need to develop in Qt for Fremantle.

EDIT (4/27): As it turns out, pulling down the Maemo toolchain using the package manager is no longer possible. So, version 1.1.2 of the SDK is probably no longer usable (unless some alternative way to retrieve the toolchain becomes available).

However, it turns out that version 1.1.1 of the SDK contains the toolchain in its installer, so there is no need to pull it down using the package manager. Therefore, 1.1.1 is still usable for developing Fremantle apps.