REAPER is a complete digital audio production application for Windows and OS X, offering a full multitrack audio and MIDI recording, editing, processing, mixing and mastering toolset.
I like that you can use it to record multiple instruments at once without having separate tracks or plug-ins. For example if there's an instrument which doesn't have its own track; but rather has some effects with other instruments in another tab of your project manager window (which acts as your mixer) then you'll be able to mix those two together while using just one instance of reaper instead of opening up each individual plugin/track separately.
This makes my work much easier since i don't