Question: Who did the Oceanic Preservation Society and The Orca Project write letters to?
About the article "Blackfish (film)", section "SeaWorld response".

Candidate passages:
SeaWorld Entertainment refused to take part in the production of "Blackfish", and later claimed the film was inaccurate, saying in a statement:SeaWorld responded further with an open letter rebutting the claims.
The Oceanic Preservation Society and The Orca Project, a non-profit focusing on orca in captivity, responded with open letters criticizing SeaWorld's claims.
Marine researcher Debbie Giles also offered rebuttals to SeaWorld, finding its assertions inaccurate.
SeaWorld also created a section of its website titled "Truth About Blackfish," addressing the claims stated above and highlighting other problems with the film:
The implication that SeaWorld separates mothers and very young calves, pointing out that Tillikum was not collected by SeaWorld; that Takara was 12 years old when moved and Kalina was moved when she was over 4 years old.
The inclusion of a SeaWorld video of a female trainer riding a killer whale, while one of the cast members, Samantha Berg, talks about her experience at Shamu Stadium, pointing out that the segment implies that Berg had relevant experience when the video used in the film was actually shot 10 years "after" Berg had left SeaWorld (The trainer depicted in the video is not Berg but rather a current SeaWorld employee at the time of "Blackfish"'s production).
The film's use of animal rights activists who have aggressively campaigned against marine mammal display and have no expertise with killer whale behavior in captivity, specifically Howard Garrett, Lori Marino and Ken Balcomb; the film's reliance on statements by David Duffus, a professor of geography whom Occupational Safety and Health Administration’s (OSHA) Judge Kenneth Welsch found "has no expertise in the training of captive killer whales."
The film's use of false and misleading statements about the circumstances of Brancheau’s death, specifically the opening sequence's separate generic training and performance footage edited together and synched with actual 911 calls, "to mislead the audience into believing it is viewing the actual footage of Ms. Brancheau swimming with Tilikum prior to the fatal incident," when the opening sequence does not depict either Brancheau or Tilikum, or even an attack, and that no one was ever allowed to swim in the water with Tilikum, including Brancheau; and the use of an edited recording of an EMT technician, subsequently proved to be mistaken, suggesting that Tilikum swallowed Brancheau’s arm during the attack.
On February 27, 2014, SeaWorld filed a complaint with the U.S. Department of Labor, claiming the Occupational Safety and Health Administration investigator who investigated Brancheau's death had behaved unethically by aiding the filmmakers.
Cowperthwaite denied claims of improper collaboration.
In March 2014, Cowperthwaite responded with rebuttals to several but not all of SeaWorld's website claims and challenged SeaWorld to a public debate.
Orca Engineering is a sports car company based in Liechtenstein.
Orca designs and manufactures the Orca 113 Platform, as well as the upcoming Beck LM800.
Founded in 2003, by René Beck and his son Ralph, the company is most known for the Orca 113 Platform, which came in three variants, of which only seven cars were produced.
When the Orca 113 Platform died out, René Beck decided to move on to his next supercar project, the Beck LM800. 
The following people contributed to "Bitte Orca": 
Orca is a free and open source, flexible, extensible screen reader from the GNOME project for individuals who are blind or visually impaired.
Using various combinations of speech synthesis and braille, Orca helps provide access to applications and toolkits that support the AT-SPI (e.g., the GNOME desktop, Mozilla Firefox/Thunderbird, OpenOffice.org/LibreOffice and GTK+, Qt and Java Swing/SWT applications).
The development of Orca was started by the Accessibility Program Office (APO) of Sun Microsystems, Inc. (now Oracle) with contributions from many community members.
The original idea and the first working prototype for Orca was started in May 2004 by Mark Mulcahy, a blind programmer who worked for Sun Microsystems.
When Mark left Sun Microsystems and ventured out to start his own company, the Accessibility Program Office took Mark's work, continued with it and released the first official version on September 3, 2006.
When Oracle acquired Sun Microsystems in 2010 they cut developer jobs of full-time developers working on GNOME accessibility components, including Orca main maintainer Willie Walker.
Since then, Orca is run by volunteers, led by Joanmarie Diggs.
In September 7, 2011, Igalia, a company specialized in Free Software, hired Joanmarie Diggs and is supporting her work in Orca.
The name Orca, which is another term for a killer whale, is a nod to the long-standing tradition of naming screen readers after aquatic creatures, including the Assistive Technology product on Windows called JAWS (which stands for Job Access With Speech), the early DOS screen reader called Flipper, and the UK vision impairment company Dolphin Computer Access.
As of GNOME 2.16, Orca is the default screen reader of the GNOME platform, replacing Gnopernicus.
As a result, Orca follows the GNOME stable release cycles of approximately six-months.
Orca is provided by default on a number of operating system distributions, including Solaris, Fedora, openSUSE and Ubuntu. 
Keiko (earlier Siggi) (c. 1976 – December 12, 2003) was a male orca who is best known for portraying "Willy" in the 1993 film "Free Willy" and an attempt to reintegrate the whale into the wild.