My personal copy of the Rubáiyát of Omar Khayyám does not have the Third Edition introduction, nor the notes that accompany the Fifth Edition, so those portions of these web pages have not been proofed, nor marked up with the accents and font changes. Other than minor changes, they are as-is from the public domain etext.
The copy of the Rubáiyát of Omar Khayyám I acquired in 1974 (an old, beat up library discard) suffers from the "slow fires" problem—acidic paper that slowly "burns" away—common to many books from the mid-19th to mid-20th centuries. So, I decided to put it online before it got too fragile to handle.
Rather than scan/OCR the text, I acquired a plain text copy from Project Gutenberg. I've corrected some mistakes, added accents and fonts, and other minor changes to make it correspond as closely as possible to the book. I've retained the extra text in the Introduction from the third edition, and the Notes for the fifth edition, but they are unverified.
In the book, each stanza of the First Edition is accompanied by artwork by Edmund J. Sullivan. What I hope will make this site different from most Rubáiyát sites is this collection of scanned illustrations. They're just quick and dirty monochrome gifs, at least for now.
Brief rant: apparently a cybersquatter is sitting on www.gutenberg.org; if you go there you'll see it's for "sale or rent", $1000 minimum. It also has those annoying online gambling ads. The .com and .net domains seem to be in similar limbo.
The small-caps font variant doesn't appear to be handled correctly by my browser, so I have a hack in the style sheet. I'll probably re-do this later. Sorry about that.