The future is here - and it's not as impressive as you might think. Sure, strides have been made in technology, computer systems, genetic manipulation, and just about any problem that can be solved by throwing money and a lot of talented young BellLabs scientists at it, but at core, people are still as ugly, squirming, afraid and ignorant as they always have been. And there are still sparks of brilliance, and moments of epiphany, and they are just as likely in 2038 to be drowned out by a moment's sorrow or distraction as they are today.
Computers have gotten smaller, faster, and cooler-running, of course. There are 6 ghz eight-core chips at the top edge of the market; more common is 7 ghz quad-core. The average 'home computer' can be fit into a head unit, a wrist-mounted box the size of today's iPod, or anything else of similar size; A mainframe or server class computer is the size of today's largish laptops. The metaverse is here(through the use of VR headsets), courtesy of a small San Fransisco-based company founded around 2001. Medical technology has advanced to the point where the average lifespan is projected at 110. The human genome is not just mapped but understood and engineered to the point where just about any genetic defect can be repaired at birth, or any desired trait tweaked in.
Most of the main characters in this story. There are two biological and four legal classifications of splicers.
Biology of a Splicer
First Generation: First Generation splicers are small(5' - 5'5"), fast, and have efficient metabolisms. Due to their rigidly controlled diets during their youth and said metabolism, there are no recorded overweight first-gen splicers, though obviously muscle mass and body fat ratios are going to vary with the individual. Most have clawed fingers and toes, and on occassion the foot structure has been so altered that the individual cannot wear shoes of any sort. The skull is elongated somewhat in the front, giving the appearance of a 'muzzle'; however, this is kept to a minimum so as to not affect speech abilities. There is very little gender dimorphism due to the influences of the animal DNA, and secondary sexual characteristics are present but understated; additionally, all subjects are sterile. The spine in most cases has developed outward into a tail and this grants splicers an immense balance advantage over unspliced individuals. The subjects retain the hair on their heads despite the hairlike fur that grows on the rest of their body. Fur patterns seem to mimick the markings of the source species. Most subjects retain an omnivorous diet, though they may show meat/vegetable preferences depending on the source species. All are ambidextrious and most have straight hair.
Second Generation: Second Generation splicers fall on the short end of the human height range(5'3" - 5'8"), tend to be physically more muscular than first-gens, and a bit slower, but still far faster than normal humans. Second gens are typically developed as a generic mishmash of either canid, feline, or rabbit-like DNA, depending on whether they are being used for manual labor, manufacturing, or what have you. Occassional special batches can be designed with another species to suit a specific need. They are generally grown in large groups of genetically identical individuals and given name-number combinations. They have clawed fingers and toes, feet that fit well inside human shoes, and the same slightly elongated frontal face structure and spines as the first-gens. They are sexless and androgynous, in addition to being sterile. The fur and hair is engineered to have an unnatural silver color to make them easily told apart from the first-gens.
Currently my thought is that this story is set in Philadelphia, since it's a city I grew up near and know fairly well - an older, industrial american city without the flash or tourist appeal of New York or San Francisco.