Simplify the following text for a Grade 10 native English-speaking person.
Original: Abdurrahman Wahid , born Abdurrahman Addakhil ( 7 September 1940 â `` 30 December 2009 ) , colloquially known as , was an Indonesian Muslim religious and political leader who served as the President of Indonesia from 1999 to 2001 .
Simplified: KH Abdurrahman Wahid ( September 7 , 1940 â '' December 30 , 2009 ) , called Gus Dur , was the president of Indonesia from October 20 , 1999 to July 23 , 2001 .