I use Lilypond, which is uses the General Public License (GPL). It is very flexible, and can do almost anything that Musescore, Finale and Sibelius can do (I also have version 5.2 of the latter). Lilypond can easily handle guitar notation such as string numbers, fingering, etc. It can handle quite obscure notation if necessary. It is easy to turn tablature on and off. Yes, you have to enter the notes and duration, etc., using text. However, with practice, that becomes quite a quick process. I find the output looks very good without adjustment, but there is a lot of information on how to tweak the look, and to manage clashes when the music is very dense. It is also possible to create libraries of standard notation specific to particular instruments, and macros to enter frequently used commands using abbreviations.
Because Lilypond uses text input, I use the GPL licensed Frescobaldi as a GUI, which prepares a pdf output and displays it in a separate window. Clicking on notes in the pdf window highlights the text note, and vice versa. It also prepares a midi file (if turned on), which can be played back. I use VirtualMIDISynth as the midi playback device (rather than the default windows player)--that way different sound files can be used. RealFont_2.1.sf2 gives a very realistic classical guitar sound.
IMO Lilypond/Frescobaldi is a good option; the programs are frequently updated, and they are free!