A Friend recently made a video reviewing this new OSHD client. It looks awesome, although Jagex doen't approve of 3rd party clients, but it still doesn't stop people from using them. Same for Rwt, it's against the rules, but if you're buying you will never get banned, because they wouldn't want to lose their players.
Old School Runescape in HD
Here's the video of Dovydas talking about the client and showing you how great everything looks in HD.
The client looks amazing and the quality brings a lot of life to this game. Hopefully nothing goes wrong with this client and it will be available to everyone who wants to use it as at the moment it costs money to use it, however, A Friend is offering you to claim a free trial on this client.
Also if you haven't seen this yet, check out the 1st Infernal Cape in OSRS by Woox.