The Web site, www.robertandgladys.com, said it aims to counter the way Zimmerman has been "savagely portrayed in the media" for the shooting death of Trayvon Martin, 17, in February, ABC News reported Friday.
Robert and Gladys Zimmerman detail the family's lives, from the story of how the couple began dating in the 1970s to the death threats they've received since the shooting.
Robert Zimmerman said he and his wife have received a barrage of threatening phone calls, particularly since actress Roseanne Barr published their address and phone numbers.
"Almost immediately, threatening phone calls and letters were received," he wrote. "However, one in particular was alarming because it threatened to kill anyone with George's DNA -- it was not mailed, but was left at our front door."
Included on the Web site is a section requesting contributions to the couple's "greatly increased living expenses" as they travel from hotel to hotel avoiding threats.
"It's been a challenge getting hotel rooms when we cannot provide our correct names, use credit cards or produce any valid identification," he wrote. "Today, that is very much what our existence is. ... There have been other severe hardships. However, for security reasons, these cannot be mentioned at this time."