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 

v3.1 (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.

 PERMSSN    UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]                  676    1197  56.5% -lh5- 2126 Oct 14  2000 amimsx/AmiMSX.info
[generic]                 9598   35772  26.8% -lh5- 1a7c Sep 25  2000 amimsx/amimsx/Keyboard.iff
[generic]                  713    1496  47.7% -lh5- ba4d Sep 25  2000 amimsx/amimsx/Keyboard.iff.info
[generic]                 4836    6780  71.3% -lh5- eed1 Feb 17  1980 amimsx/devs/mfm.device
[generic]                 1843    2480  74.3% -lh5- 4325 Aug 31  1994 amimsx/devs/statram.device
[generic]                 2292    8960  25.6% -lh5- 7ea0 Oct 14  2000 amimsx/Install
[generic]                  929    1709  54.4% -lh5- dae7 Oct 14  2000 amimsx/Install.info
[generic]                 4520    6368  71.0% -lh5- 5a0d Jul 24  1997 amimsx/libs/Stc.library
[generic]                 1548    1576  98.2% -lh5- 178b May  4  1999 amimsx/s/AmiMSX2.key
[generic]                  668    1669  40.0% -lh5- 1bd3 Sep 25  2000 amimsx/amimsx/AmiMSX.guide.info
[generic]                  267     628  42.5% -lh5- 6863 Sep 25  2000 amimsx/amimsx/MSX_Drivers.info
[generic]                  430     716  60.1% -lh5- 2217 Jan 29  1994 amimsx/amimsx/msx_drivers/RAMSX
[generic]                17921   22468  79.8% -lh5- 2302 Sep 25  2000 amimsx/amimsx/mvd_files/Ark-A-Noah.MVD
[generic]                64791   72856  88.9% -lh5- 97aa Sep 25  2000 amimsx/amimsx/mvd_files/Sex Bomb Bunny.MVD
[generic]                  627    4872  12.9% -lh5- fa7b Jan 27  1996 amimsx/amimsx/mvd_files/Speed Test.MVD
[generic]                76379   83540  91.4% -lh5- dbe8 Oct  3  2000 amimsx/amimsx/AmiMSX
[generic]                 1412    6107  23.1% -lh5- a859 Sep 25  2000 amimsx/amimsx/AmiMSX.info
[generic]                11007   11230  98.0% -lh5- 3544 Jun  7  1996 amimsx/amimsx/cartridges/Basic Kun.ROM
[generic]                 9561    9790  97.7% -lh5- c4f3 Apr  2  1997 amimsx/amimsx/cartridges/FM Pac.ROM
[generic]                11219   11536  97.3% -lh5- ad31 Jun  7  1996 amimsx/amimsx/cartridges/Kanji.ROM
[generic]                  306     530  57.7% -lh5- a58f Sep 25  2000 amimsx/amimsx/msx_drivers/RAMSX.info
[generic]                  433     715  60.6% -lh5- 7dc8 Oct 14  2000 AmiMSX.readme
[generic]                 8682   27324  31.8% -lh5- 356b Oct  1  2000 amimsx/amimsx/AmiMSX.guide
[generic]               244224  244224 100.0% -lh0- bceb Sep  5  1997 amimsx/amimsx/AmiMSX2.data
[generic]                  180     180 100.0% -lh0- 11e6 Jul  9  2000 amimsx/amimsx/AmiMSX2.mapper
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total        25 files  475062  564723  84.1%            Jul 21 16:30