FOSS Remote Desktop SW

Source

P r o g r a m	P r o t o c o l	L i c e n s e	Client	Server	Java Viewer	Built-in Encryption	File Transfer	Audio Support	Multiple Sessions
C h i c k e n V N C	R F B (V N C)	G P L		X	X	X	X	X	X
C r o s s l o o p	R F B (V N C)	G P L			X	AES -128		X	X
E c h o V N C	R F B (V N C)	G P L						X
F o g C r e e k C o p i l o t	R F B (V N C)	G P L			X	SSL		X	X
F r e e N X	N X, R D P, R F B (V N C)	G P L	X		X	AES
j r d e s k t o p	P r o p r i e t a r y	G P L				SSL, TLS		X
r d e s k t o p	R D P	G P L		X
R e a l V N C F r e e	R F B (V N C)	G P L				X	X	X
S S H w i t h X f o r w a r d i n g	X 1 1	B S D			X		X	X	[Note]
T i g h t V N C	R F B (V N C)	G P L				X		X
x r d p	R D P	G P L	X		N/A		X	X
X 1 1 v n c	R F B (V N C)	G P L	X			SSL		X

Note No sessions at all, just individual program windows. However you can use Xnest if you want.