Android App development without Virtualization Technology?

As the name implies, it is an Emulator Accelerator. You can still use the Emulator, its just going to be a bit slower running without HAXM.

In my experience, it is OK to use the normal emulator for infrequent debugging but it is too slow, even with HAXM, for serious development, which should be carried out on an actual device.

If you have to use an emulator, I'd go with GenyMotion.