Just saw a reference to this on another forum: Visual Studio Code (Beta) for Windows, Mac, and Linux:
https://www.visualstudio.com/pro... Official release expected mid-2017.
I am almost afraid to hold my breath! Would suffocate, first! On the other hand, maybe there is hope! I sure do hope that Atmel is keyed into this!
M$ is also releasing MS SQL Server for Linux! This is right on par with Hell Freezing Over!
Jim
Point ... counterpoint
Apple Xcode
Be around one who's an Apple fanboy or fangirl ... you'll know what I mean 
There's an embedded version that has a lot of boards with debuggers for :
GDB is stated with one GDB server (OpenOCD).
So, might be possible to add AVR-GDB to this IDE with some effort; there is an AVaRICE (AVR GDB server) and an AVR GDB client on Mac OS X.
Debugging is in a terminal window with a possibility that debugging will be integrated into Xcode.
Big manual (511 pages, 78MB)
There's an AVR framework for it that's an alternative to Arduino; boards :
https://www.adafruit.com/products/2772, Adafruit Feather M0 Basic Proto
https://learn.adafruit.com/proper-step-debugging-atsamd21-arduino-zero-m0?view=all
http://embedxcode.weebly.com/la_selectdownload-ygzuzhx8ggabc4w.html, embedXcode, Download
http://embeddedcomputing.weebly.com/cosa-an-alternative-framework-for-avr-boards.html
https://github.com/mikaelpatel/Cosa/tree/master/boards
Edit : SEGGER
embedXcode
Projects
http://embedxcode.weebly.com/projects.html
...
Office Chairiot MK-II
...
The creator is in Arizona ... land of free spirits 
Visual C++ Team Blog
C/C++ extension for Visual Studio Code
March 31, 2016
https://blogs.msdn.microsoft.com/vcblog/2016/03/31/cc-extension-for-visual-studio-code/
...
Today we are announcing a Preview of a product for your C/C++ editing and debugging needs on Linux and OS/X: the C/C++ extension to Visual Studio Code.
...
... this preview version of the C/C++ extension introduces a better language service experience with support for code-navigation and the ability to debug C/C++ applications ...
...
Debugging your C/C++ application in Visual Studio Code
...
The debugging experience currently only works out-of-the-box for Linux – Ubuntu 14.04 (x64).
We are working on OS X support as well ...
...
GDB and MI commands
...
"Microsoft is sharing code between Visual Studio and Visual Code. This extension requires .Net because of the debbuger engine ..." - Felipe
...
(wrt Clang)
"Our LLDB support in the extension isn’t quite ready for public consumption, but watch the extension for future updates.
It is currently possible to point this extension to very recent builds of lldb-mi (3.8 or 3.9) but that scenario hasn’t been tested and has some known issues." - Jackson Davis
...
"It’s not that C/C++ code is not supported on Windows, it’s just that the debugging portion of the extension currently doesn’t support Windows debugging.
The primary reason for that is exactly that the debugger engine uses GDB MI which doesn’t help with debugging standard COFF, PDB all that much." - Ankit Asthana
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"The same tag-parser which parses symbols in your source code and provides the code-navigation features on Visual Studio on Windows has now been ported over to Mac and Linux which we hope provides the fastest code-navigation experience :). " - Ankit Asthana
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http://lldb.llvm.org/ (The LLDB Debugger)
InfoWorld
Bossie Awards 2016: The best open source application development tools
Sep 21, 2016
Visual Studio Code
...
... C++ ... support IntelliSense, outlining, and linting, but not refactoring.
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VS Code runs on OS X, Linux (both Debian and Red Hat distros), and Windows.
VS Code on Windows requires .Net Framework 4.5.
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Visual Studio Marketplace
Native Debug
by webfreak
https://marketplace.visualstudio.com/items?itemName=webfreak.debug
GDB, LLDB & Mago-MI Debugger support for VSCode
...
Using
gdbserverfor remote debugging (GDB only)...
Federico Zuccardi Merli
9/4/2016
I'm using this for embedded debugging, through OpenOCD and other gdb servers. No major issues, ...
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westfw posted this https://www.avrfreaks.net/forum/no-mac-os-x-version-atmel-studio-7#comment-2053951
More :
The Visual Studio Blog
Announcing the new Visual Studio for Mac
by Miguel de Icaza (Distinguished Engineer, Mobile Developer Tools, Xamarin co-founder, GNOME co-founder)
November 16, 2016
https://blogs.msdn.microsoft.com/visualstudio/2016/11/16/visual-studio-for-mac/
...
... you’ll find the same Roslyn-powered compiler, IntelliSense code completion, and refactoring experience you would expect from a Visual Studio IDE.
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- Highly optimized native code backed by the LLVM optimizing compiler
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https://blogs.msdn.microsoft.com/visualstudio/tag/visual-studio-for-mac/
https://github.com/dotnet/roslyn
The .NET Compiler Platform ("Roslyn") provides open-source C# and Visual Basic compilers with rich code analysis APIs.
Just saw a reference to this on another forum: Visual Studio Code (Beta) for Windows, Mac, and Linux: ...
Visual Studio Marketplace
PlatformIO
https://marketplace.visualstudio.com/items?itemName=formulahendry.platformio
...
Integrate PlatformIO into Visual Studio Code on top of PlatformIO Core. Cross-platform Build System without external dependencies to the OS software: 350+ embedded boards, 20+ development platforms, 10+ frameworks. Arduino and ARM mbed compatible.
Atmel AVR & SAM, Espressif 8266 & 32, Freescale Kinetis, Intel ARC32, Lattice iCE40, Microchip PIC32, Nordic nRF51, NXP LPC, Silicon Labs EFM32, ST STM32, TI MSP430 & Tiva, Teensy, Arduino, ARM mbed, libOpenCM3, ESP8266, etc.
...
via
https://github.com/platformio/platformio-core/issues/619
via
http://docs.platformio.org/en/latest/history.html#id1 (3.3.0 2017-03-27)
http://docs.platformio.org/en/latest/ide/vscode.html
The Visual Studio Code extensions relative to AVR :
PlatformIO PIO Unified Debugger is a value-added part of PlatformIO (PlatformIO Plus) for arm and Texas Instruments MSP430TM
Microsoft Arduino has an integrated debugger though only for Microchip SAM (EDBG) and two Microchip competitors.
FastArduino invokes macOS and Linux Microchip AVR GCC 3.5.4 though may be up to 3.6.1 approximate to the end of April'18.
Consider replying into Jim's thread when you are aware of other relevant or related Visual Studio Code extensions.
https://marketplace.visualstudio.com/items?itemName=platformio.platformio-ide
https://platformio.org/pricing
https://marketplace.visualstudio.com/items?itemName=vsciot-vscode.vscode-arduino
https://marketplace.visualstudio.com/items?itemName=jfpoilpret.fastarduino
https://github.com/jfpoilpret/fast-arduino-lib#milestone-v11-30042018
https://marketplace.visualstudio.com/search?term=tag%3Agdb&target=VSCode&category=All%20categories&sortBy=Relevance (Cortex-Debug, Native Debug)
Edit: target
