Packet Tracer 6.3 has been released on 22th december 2015 with version number 6.3.0008. This version was the first Cisco Packet Tracer version freely downloadable for everyone on the official Netacad website . A free netacad account can be created by everyone and Packet Tracer is not reserved to netacad students anymore. Cisco released this version in a single package and didn't reconduct the separation between "Cisco Packet Tracer Student" and "Cisco Packet Tracer Instructor".
There is no new feature in this version which introduces Netacad login at program start. Netacad users have to login using their cisco credentials. A guest access to Packet Tracer is still possible with a 15s wait time at program startup.
Packet Tracer 6.3 is fully compatible with labs created in Packet Tracer 6.2, 6.1.1, 6.0.1 and 5.X. All labs provided in the CCNA Exploration, CCNA Discovery, CCNA Security, and IT Essentials curricula are also supported with Packet Tracer 6.3
All other major new features where introduced in Packet Tracer 6.2 : HTTP server improvments, Cisco 819 Integrated Service Router with wlan access point capability and 3G/4G connectivity, 3G/4G telephony cell tower, 3G/4G central office (CO) server with coaxial connectivity with up to 8 cell towers, network sniffer... Read our Packet Tracer 6.2 review
Known issues in Packet Tracer 6.3
When a phone is attached to a switch the "show mac address-table" command shows an incorrect MAC address for the phone. Correction of this bug has been schedulded in the development rodamap.
When working with switches under PT, there is no difference into cyrptographic IOS (k9 images) and non cryptographic IOS: in any case you can activate SSH and create RSA keys. Should be corrected in the next Packet Tracer release.