El Capitan is the name of the publishing company started by writer/artist David Lapham in 1995 in order to independently publish his comic book Stray Bullets, after his departure from Defiant Comics. David's wife Maria Lapham serves as the publisher and in an editorial and customer service capacity.
The company has published 28 issues of Stray Bullets (along with 3 hardcover collections and 6 softcover collections of the title), 9 issues of Murder Me Dead (along with 1 hardcover and 1 softcover collecion of the title) and 2 issues of Amy Racecar Color Special, along with numerous t-shirts and stickers related to the titles published.
Sources:
Robert M Overstreet. The Overstreet Comic Book Price Guide, 31st Edition. New York: Crown Publishing Group. 2001.
http://www.thefourthrail.com/reviews/snapjudgments/102901/murdermedead9.shtml
1998 discussion with David and Maria Lapham