For anyone interested in Nintendo DS emulation -- DeSmuME has been updated to v0.9.11! This was a very Mac-focused released, with some features being Mac-only. If anyone has given up on Mac DeSmuME in the past due to its former bad reputation, I strongly encourage you to try out v0.9.11. DeSmuME has finally gotten past the bad old days of v0.9.6.

Enjoy!

From the v0.9.11 release notes:
In this version, we have focused on the Cocoa frontend, but there have been some good core fixes over so long. Notably, the save-related issues resulting in the advice "dont use 0.9.10" have been resolved.

General/Core:

bug: fix large numbers of games not being able to save anymore
bug: fix some missing sound effects due to wrong volumes in some boot scenarios and other things
bug: fix freezes due to tiny looping sounds
bug: fix many big endian issues
bug: fix some apparently rarely-used CPU instructions, no known consequences
bug: fix (block) reading of some GPU registers
bug: fix action replay code type 0xE
bug: fix reading of last 4 bytes of rom
bug: large improvements to stability of GDB stub
bug: support w-buffer support in OpenGL renderers
bug: fix unpredictable crashes in some 3d scenes from w=0
enh: better loading of roms (bad patches) with wrong size info in header
enh: warn user sometimes when 'stream rom from disk' will create malfunctions
enh: add xBRZ filters
enh: add "TXT Hack" for software rasterizer to improve text rendering in some games

Cocoa:

bug: 16-bit to 32-bit color space conversions no longer darken video or images
bug: fix intermittent issues with loading user defaults on app startup
bug: fix rendering inaccuracies of the video preview in the app display preferences
bug: fix various UI font rendering and text alignment issues on OS X Yosemite
bug: fix crackly sound from N-sync and Z-sync methods
enh: make N-sync method the default sound sync method since it has much lower latency than P-sync method
enh: add support for gdbstub (Tools > Show GDB Stub Control) (only available on custom builds using the dev+ build target)
enh: optimize input handling to use less CPU
enh: add support for App Nap when the app is in an idle state (only supported on OS X Mavericks and later)
enh: add Execution Control panel (Emulation > Show Execution Control), now with frame advance and frame jump controls
enh: auto frame skip is now smoother
enh: further improve execution timing accuracy
enh: improve overall video performance
enh: render video through a 3-stage filtering pipeline, (Video Source)-->(Pixel Scaler)-->(Video Output)
enh: add the following video source filters - Deposterize
enh: add the following video output filters - Bicubic B-Spline, Bicubic Mitchell-Netravali, Lanczos2, Lanczos3
enh: add ability to run all existing pixel scalers on either the CPU or the GPU
enh: add ability to toggle the main and touch display positions (View > Toggle All Displays)
enh: add preliminary support for replay playback and recording
enh: add support for turbo and autohold
enh: add support for the entire suite of slot-2 devices (Emulation > Show SLOT-2 Manager)
enh: add support for using the host machine's audio input device for emulating the NDS microphone (Emulation > Show Microphone Settings)
enh: change the sine wave tone generator's range from 100Hz-5000Hz to 40Hz-4000Hz
enh: reorganize the menu options to more logical locations
enh: greatly improve the File Migration Assistant (now renamed Game Data Migration Assistant) and ROM Info panel with a more modern and space efficient look and feel
enh: miscellaneous user interface improvements