Donna's World

Donna's World is the  alternate universe created when Donna Noble turned right, to go for a job interview to become the personal assistant of Jival Chowdry.

Origin
Donna was unknowingly fitted with a time beetle by the Trickster's Brigade while on Shan Shen. While the bug was attached, the fortune teller suggested her what would have happened if at some point in her life she had turned right instead of left, and due to that suggestion Donna's history changed changed accordingly.

Donna, long before meeting the doctor, had two jobs available, one with H.C. Clements in the centre of London, or another as the personal assistent of Jival Chowdry. While in the car and and discussing with her mother the two job opportunities, her mother pressures her into "turning right" and check out the business of Jival chowdry.

While in the regular timeline Donna ignored her mother and turned left, in this timeline she turned right, resulting in her taking the other job.

Alternate History
As the Doctor dies, various events set on contemporary Earth, go differently as he is unable to interween.

"The Runaway Bride"
The Doctor died while fighting the Racnoss, as Donna Noble wasn't there to stop him. UNIT declared him dead, dying too fast to regenerate. Rose Tyler meets Donna Noble for the first time. Donna Noble is later sacked from her PA job.

"Smith and Jones" and Series Three
With the exception of Oliver Morgenstern-- who survived as Martha Jones gave him her last piece of air--, all patients and staff of Royal Hope Hospital died of oxygen starvation. Sarah Jane and Luke Smith, Clyde Langer, Maria Jackson and Martha Jones were notable deaths.

The Doctor never met Martha, and therefore couldn't save the hospital. The events of The Lazarus Experiment and The Sound of Drums (the events of Last of the Time Lords were negated during the Series 3 finale.)never happened, as the Doctor, Martha and Captain Jack Harkness never went to Utopia to remind Professor Yana that he was the Master. So the Mr Saxon regime could never have started.

"Voyage of the Damned"
The previous Christmas's (DW: The Runaway Bride) events had gone differently so most Londers didn't flee the city, as they had in the "left" timeline. Wilfred Mott never meets the Doctor.

A Titanic replica, crashed and destroyed the whole city. Astrid Peth never met the Doctor, and was likely to have died during the crash. Most Londers, who notably didn't flee this year, all pershied. Notable exeptions include Wilfred Mott, Donna and Sylvia Noble; as Donna was told to go on holiday that Christmas, by Rose Tyler.

As London is destroyed, most of Southern England is infected with radiation. This displaces many residents of Southern England, including the Nobles. People were thrown out their houses for small things such as missing a single mortgage repayment, to make up for the lack of housing. The Nobles are moved into a house in Leeds, which they must share with other families.

"Partners in Crime" and "The Sontaran Stratagem"/"The Poison Sky"
America promise to financially help Britain, however sitautions arise over the Atlantic which makes them vulnerable aswell. For example, The March of the Adipose takes place there, instead of London. It is successful and many people die across different parts of the country.

As Britain is in such an unstable situation and other countries have closed their borders-- so deportation is out of the question-- they start sending "immigrants" to Labour camps. One of the families that get sent to one are living with the Nobles. Wilf, who served in World War II, is in horror. Seeing parallels between this and the Nazi regime which caused the Holocaust, saying that it had the same reasoning as "last time".

The ATMOS devices choke the world, they are shot down by UNIT in Britain. However it affects many other countries such as China alot worse. Since the Doctor, Martha and Donna never face the Sontarans, it's left to Torchwood members, Gwen Williams and Ianto Jones blow up the Tenth Sontaran Battle Fleet, sacrificing themselves in the process. Leaving Captain Jack Harkness distraught, and without a team, is transported to Sontar. Rose remarks to Donna that they were the last ones left.

Negation
UNIT and Rose Tyler send Donna back to the time where the world split. Donna must make herself turn left. She runs out of time, and realises that the only way to change the timeline is if she is ran over, blocking her past self from driving round that way.