Answer to one of the riddles. (I think)
To start, just look at the very first page, - the letter X
To follow, begin where Nemo entered into a rage. - still not sure but guessing a word starting with M. Maelstrom perhaps? Based on the ending of 20,000 leagues.
Then add to that what the Phoenicians used to see, - Orb
The end was found, fricatively wound, in the branches of the very first tree. - Snake
My whole was born in a place where a Celtic river was by Saxons, crossed, - The city of bristol, a saxon city on the river Avon (celtic for water)
A new incarnation of a parallel, once thought lost. - a new incarnation of the Transputer
Answer XMOS XCore.
http://www.xmos.com/technology/xcoreNow to sit and wait for someone on aw.net to borrow my answer without citing the source.