Treasure Island was written 130 years ago and it remains one of the great adventure tales of all time. I originally read it when I was about ten years old and, fifty years later, I recently re-read it in the Kindle edition. The fact that the book brings as much pleasure now as it did then is an indication of how good it really is. Stevenson truly hit the ball out of the park with this one.
Much has been remarked in many of these critiques about the outdated language Stevenson used. In that regard, I have to say that the Kindle edition that I downloaded lacks one thing that was included in my old printed edition, which was published by MacMillan way back in 1924. The old edition has a set of notes following the text, explaining a lot of the nautical terms and old-fashioned jargon. It even includes the complete lyrics to "A Bottle of Rum". I never found those notes necessary but they might prove useful to some of the younger readers, to whom such language might be unfamiliar. Personally, I think the language is part of what has given this tale it's lasting appeal. In addition, I don't know whether 18th Century pirates really spoke the way Stevenson has them speak in Treasure Island, but there is no doubt that it is the way they will forever be remembered, "...and ye may lay to that, Matey"!