UltraStar Deluxe was started as a modification of "UltraStar". Whiteshark initially offered to collaborate with Corvus5, but this offer was declined. Instead Whiteshark started to add some features on his own with the help of Mota. The first release is known as X-Mas mod, due to a release date around Christmas time. This attracted the attention of other developers that were willing to help. The team grew and the source code departed more and more from the original. Smaller features are often implemented in both projects allowing them to benefit from one another. Though the projects' implementations of such features often differ. "UltraStar Deluxe" is different in three key ways from UltraStar. Significant effort has been put into improving reliability by repairing bugs. The second difference is the visual appearance. Sparkling stars and various other effects have been added in addition to skin support. Many effects are also based on "SingStar" on PS3, Vocaluxe and Performous. Many new features have been implemented: