This new version of the Arduino IDE was announced at the beginning of October 2016 at the New York Maker Faire as the official, unified, desktop editor for all Arduino boards.
The major news we reported at the time was that the two warring factions of the Arduino world had resolved the issues that had led to establishment of two brand names - Arduino and Genuino. See Arduino Back To Being One Company for the full history - or simply let it be history.
Going forward Arduino 1.8.0 supports all Arduino.cc and Arduino.org boards and is ready for download.
The release announcement states:
Arduino IDE 1.8.0 works out of the box with AVR boards, like the Uno, Mega, Yun, and Micro, among the most popular. Additionally, it supports the Leonardo Ethernet, Yun Mini, Industrial 101, and Uno WiFi.
The updated SAMD core will provide support for the M0 and M0 PRO, completing the product line that includes the Zero, MKR1000, and the newly-launched Primo and MKRZero.
On the technical front, users can run the IDE on Linux directly in command line, no longer requiring the X11 display. Also Arduino Builder paths with strange UTF8 chars are now correctly handled.
Early adopters of the new IDE have complained about the fonts used by the IDE which they claim are "horrid". This issue is already being dealt with, with the explanation that it was "caused by a seemingly unrelated fix for Linux".