From their blog post:

General changelog

– CHEEVOS: Add badges for achievements, shows thumbnail images of achievements.
– CHEEVOS: Leaderboard support.
– CHEEVOS: Only disable savestates on hardcore mode if achievements are not available.
– COMMANDLINE: Fix fullscreen toggle switch.
– COMMON: Add ‘Automatically Load Content To Playlist’ feature, enabled by default.
– COMMON: Fix slowmotion ratio always being reset back to 1.
– COMMON: Optimized NBIO implementations now for Apple, Windows, and Linux. Uses mmap for Linux/Windows/BSD if/when available. File I/O should now be much faster for loading images inside the menu.
– COMMON: Native Blissbox support now for latest firmware as of writing (2.0). Implementation through libusb and/or native Windows HID.
– COMMON: New lightgun API.
– COMMON: New VFS (Virtual File System) API.
– COMMON: Fixed some playlist bugs.
– COMMON: New snow shader.
– COMMON: Fix Quick Menu title, no longer shows ‘Select File’.
– COMMON: Fix loading cores that require no content one after another.
– COMMON: Map Delete key to Y button for non-unified menu keyboard controls.
– COMMON: Fix for relative paths being normalised and generating a duplicate history entry.
– EMSCRIPTEN: Fix references to browserfs.
– FREEBSD: Support libusb HID input driver.
– HAIKU: Buildfix.
– INPUT: Map clear button to DEL key.
– LINUX/X11: Add RetroArch logo to window title bar.
– LINUX/X11: Input driver now supports new lightgun code.
– LINUX/X11: Support window transparency (requires a compositing window manager).
– LOBBIES: Fix for crash on join netplay rooms via touch / glui.
– LOCALIZATION: Update Italian translation.
– LOCALIZATION: Update Japanese translation.
– LOCALIZATION: Update Portuguese-Brazilian translation.
– LOCALIZATION: Update Polish translation.
– LOCALIZATION: Update Russian translation.
– MENU: Snowflake menu shader effect.
– OSX/PPC: Fix the GL2 renderchain, had to use EXT versions of framebuffer/renderbuffer functions.
– PS3: HTTP requests / downloads should now work.
– PS3: Core Updater now works.
– PS3: Improved font rendering, enable STB Unicode font renderer.
– PSP: Make it work with Vita’s Adrenaline.
– PSP: Fix audio sync.
– PSP: Fix content loading, port should be functional again.
– PSP: Use 64MB when available.
– SCANNER: Fix crash from Windows-incompatible format string.
– VITA: Improve packaging, installation times.
– WIIU: Disabled the controller patcher for now since it was the source of many stability issues.
– VULKAN: Various stability fixes for WSI.
– WINDOWS: Add MSVC 2017 solution.
– WINDOWS: Get rid of the empty console window in MSVC 2010 builds.
– WINDOWS: Raw input driver now supports new lightgun code.
– WINDOWS: Use configured OSD/text message color on GDI driver.
– WINDOWS/XINPUT: Populate XInput VID/PID from DInput so autoconfig doesn’t rely solely on joypad names
– WINDOWS/XINPUT: Fix crash that occurs in some situations with Steam running and a Steam Controller plugged in.
– WINDOWS: Improve version reporting under System Information.
– WINDOWS: Support window transparency.
– WINDOWS: Correct usage of GetWindowPlacement per MS docs, fixes game window position on Win95/98.
– WINDOWS: Added Visual Studio 2017 support.

Highlights

Integrated Bliss-box support

Bliss-Box 4-Play integration for RetroArch will soon be here! https://t.co/JekUx2Gyz0pic.twitter.com/lNbIrqiaVN

— libretro (@libretro) December 13, 2017

Grab the newest firmware for this device and you can enjoy out-of-the-box Blissbox support with RetroArch on the following platforms:

• Linux
• Windows

For more information, read this separate article here.

This is a legit game changer. This peripheral will allow you to use real physical gamepads from all sorts of different game consoles through one interface.

Right now, only one of these devices is supported.

Badges for achievements

GameDragon and @andress430 added badge images to the list of achievements in RetroArch. Much nicer now! pic.twitter.com/NB9aNO90wr

— Andre Leiradella (@leiradel) November 24, 2017

Improved lightgun support

Virtua Gun pull request for @libretro submitted to github. Works really well with a Wiimote. Very pleased that you even have to aim ‘off-screen’ to reload. Right-clicking in mouse mode is such a … cop-out pic.twitter.com/Bou4ynEia2

— David Walters (@HiddenAsbestos) November 19, 2017

Lightgun and mouse support has been added to both Beetle PSX and Beetle/Mednafen Saturn.

In other input-related news, mouse support has also been added to Beetle/Mednafen PCFX.

Windows 95/Windows 98 (non-SE) support

A new RetroArch is coming out today, and unlike so many other programs, we are actually going back even further in time and supporting even more old/ancient computers! Now it’s Windows 95/Windows 98 First Edition’s turn! pic.twitter.com/nFQiTV3fX7

— libretro (@libretro) December 26, 2017

In a time and era where big companies get lazy and just throw away 32bit support for anything from drivers to operating systems, we have gone to the complete opposite side of the spectrum and started adding even more ancient/obsolete systems instead.

We already had a Windows 98 Second Edition/Millennium Edition/Windows 2000 version of RetroArch. But now, we go back even further in time! The MSVC 2003 version is a version of RetroArch that works on Windows 95 and Windows 98 (the First Version, before Second Edition).

Some things you should know about this version:

• Rough around the edges, has been mainly tested so far on VMs (Virtual Machines) instead of real hardware.
• Uses GDI as the default video driver. Our Direct3D driver so far requires DirectX 9 and Cg. It will take some work to make it backwards compatible with DirectX8.
• We omitted the Windows NT 3.51/4 versions for now. The main issue with these versions is that they do not support DirectInput, so we have no real input drivers available for them.

Right out of the gate, there are 21 cores available for the Windows 95/98 version. Not too shabby, eh?

For more information, read this separate article here.

Improved PlayStation3 port

clienthax from the @rpcs3 team has helped us significantly improve RetroArch PS3! Core Updater, netplay and downloading assets and other files is now supported! And you can run it with the @rpcs3 emulator itself of course! pic.twitter.com/dtdEikSKiX

— libretro (@libretro) December 26, 2017

So many important improvements that have been made to the PlayStation3 port as a result of our newfound friendly collaboration with an RPCS3 dev:

• • Downloads now work
  • Netplay now works. You can netplay between two PS3s, or with another system that is also of the big-endian architecture. For instance – netplay between RetroArch PS3 and RetroArch Wii U works. NOTE: There might still be some endian-specific code in certain cores that can cause bugs.
  • Content Downloader works. You can download many demos and freeware homebrew games from this.
  • Thumbnail Downloader works. You can download boxarts and titles/snaps for your games from here.
  • Core Updater works. Now you can directly download freshly updated cores directly through the built-in Core Updater. New cores will be added over time, and best of all, you don’t need to install a new RetroArch version in order to obtain these new cores either.
  • Improved font rendering inside the menu. Non-Western languages are now also supported by this improved font rendering, including Japanese, Korean, Chinese, Russian, etc.

New menu shader effects

@libretropic.twitter.com/L3yx6iucQz

— Radius (@radius___) December 3, 2017

PSP port works again

RetroArch PSP will work again for version 1.7.0 thanks to @frangar! This is a picture of it running inside the standalone version of PPSSPP, the PSP emulator. pic.twitter.com/O2XaGfcS5G

— libretro (@libretro) December 12, 2017

Wii U port works again

Wii U port should work fine again after some issues in previous versions.

Automatic scanning of content

This new option, when enabled, will add any new content you load from the file browser (Load Content) to your playlists. If a playlist does not already exist for the specific core and/or game, one will be created on-the-fly. This option is disabled by default, so watch the video if you’d like to learn how to enable it.

There’s more

There’s a ton more that we have properly not covered in this blog article, but we leave it up to the user to discover that for themselves.

What’s coming next for RetroArch

We will have a separate blog post on this soon, as well as more separate blog articles detailing some of the other progress that has been made on the cores front.