This is one of the best MSX2 emulators. It's free and its source code is open.
Features:

FAST. 
Smoth Scrolls. 
R-800 CPU supported. 
Z-80A Emulation highly optimized and compatible. 
One Frame screen refresh! 
MSX Disk drives supported via Amiga Disk drives. 
MSX Disk images supported (MVD:) 
Cartridges (ROM images) supported (Mega-ROMs aswell) 
100% Compatible with MC68020/030/040/060 
Line Interrupts support with screen changes in real time. 
MSX, MSX2 and MSX2+ ROMs supported. 
DOS and DOS2 ROMs supported. 
KANA ROM supported. (Kanji graphics) 
All MSX2 Screen modes supported. 
Two JoySticks ports supported. 
MSX Tape simulation support. 
MSX Mouse supported 
MSX Printer supported 
PSG and SCC Sound support. 
Cheat mode. (Find and set cheats in your games!) 
Mini-Debug mode. (Show memory and CPU registers) 
PAL and NTSC frequencies ONLY acepted. 
xpk, Stone Cracker and File Imploder decrunch support. 
Great GUI, very easy of use. 
Key file support. 
 
Limitations 


AGA Chip set Required. 
Don't work with Graphics cards. 
ONLY work with PAL or NTSC frequencies. 
 
History 
v3.2
Key requirement removed
Scalos support

v3.1 (25 September 2000) 
MSX2 Overscan mode support (Sex Bomb Bunny / MATRA) 
Screen 2 and 4 with ONE tile Bank support (Ark-A-Noah / MATRA) 
100% Compatible with all Motorola procesors (020/030/040/060) 
Z-80A Emulation is now Syncronized (Slow but more Quality) 
Now, a lot of things are 100% syncronized like a real MSX. 
Full support of Line Interrupts. 
CPU Emulation can run at Real/Fast/Turbo Modes. 
Screen 8 Sprites are now emulated with your real colours. 

v2.52 (August 1999) 
AmiMSX is FreeWare. (Included Key file Registered to the Amiga Community) 

v2.51 (7 October 1997) 
More compatibility with MC68060. 

v2.5 (10 September 1997) 
KANA ROM Supported. (Kanji graphics) 
Screen 3 emulated. (Graph Multi) 
Simulation of Japanese ROM-Bios. 
BIG Bug fixed in Z-80A Slower. 
Mini-Debug mode. 
Tape mode support. 
Refresh Internal Amiga Clock (NO more time Freezed) 
Saves MSX2 Sprites like a IFF-ILBM file. 
Some Z-80A and VDP bugs fixed. 
xpk support (Cartridges only) 
Saves ASL paths. 
Key file support.

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[unknown]                  676    1197  56.5% -lh5- 2126 Apr 10  2009 AmiMSX.info
[unknown]                68706   75504  91.0% -lh5- 04ff Apr 10  2009 AmiMSX/AmiMSX
[unknown]                 8028   25646  31.3% -lh5- 9890 Apr 10  2009 AmiMSX/AmiMSX.guide
[unknown]                  668    1669  40.0% -lh5- 1bd3 Apr 10  2009 AmiMSX/AmiMSX.guide.info
[unknown]                 1413    6107  23.1% -lh5- f5f6 Apr 10  2009 AmiMSX/AmiMSX.info
[unknown]               244224  244224 100.0% -lh0- bceb Apr 10  2009 AmiMSX/AmiMSX2.data
[unknown]                  180     180 100.0% -lh0- 11e6 Apr 10  2009 AmiMSX/AmiMSX2.mapper
[unknown]                 9598   35772  26.8% -lh5- 1a7c Apr 10  2009 AmiMSX/Keyboard.iff
[unknown]                  713    1496  47.7% -lh5- ba4d Apr 10  2009 AmiMSX/Keyboard.iff.info
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         9 files  334206  391795  85.3%            Dec 20 04:26