FamiTracker is a completely free windows program that acts as a tracker to producing music for NES and Famicom systems. The UI is really easy to understand and pretty straightforward. It allows users to export NSF files meaning music that was created within the program to be played upon the actual hardware or your own NES application.
FamiTracker also as real-time emulation of channels which is unlimited to the number of channels you have. DPCM and Internal PCM sample converters are supported as well. MIDI devices that can be used for inputs are supported along with that PAL and NTSC modes are supported by FamiTracker.
In the UI there are only two visual supports that being the waves and logo. The instrumental list is a white colored list. The program can be used on both Windows and Mac operating systems. You can add MMC5 and VRC6 into the module as sound chips by opening the module properties and using the expansion chip tool which is added into the program. It's easy to load in instrumental files as well. Currently, under the instrumental list, there are 5 buttons to choose from that being (New, Delete, Open, Save and Editor)
The amount of support that's included for a completely free software is top notch.
In terms of specs, you could run the program on a Windows XP computer using only 256MB's of ram but you might encounter issues due to buffer length that's set by default within the program FamiTracker it'self. The bare minimum you would want to run is a Windows 95 computer using around 8MB of ram but the program recommends at least 16mb of rams on the computer to make sure you don't encounter numerous amount of problems while running the program for 8Bit music.
All in all, for a completely free program it's definitely more than capable of producing quality sounds and with the amount of support, it's highly recommended to try.