You seem to have noticed the arrays of primitives, and not noticed the other collections: fannkuch-redux is all about "Indexed-access to tiny integer-sequence"

You seem to have noticed the arrays of primitives, and not noticed the other collections: fannkuch-redux is all about "Indexed-access to tiny integer-sequence" so it really is all int[] meteor-contest int[] byte[] OkPieces[] SPiece[] Piece[] fasta byte[] double[] frequency[] spectral-norm double[] Approximate[] reverse-complement byte[] int[] ArrayList<byte[]> LinkedList<Integer> mandelbrot byte[][] double[] Thread[] and then the ones you didn't mention: binary-trees custom binary trees chameneos-redux ArrayBlockingQueue<Creature> Creature[] Thread[] knucleotide byte[] int[] LinkedBlockingQueue<AbstractCounter> ArrayList<LinkedBlockingQueue<WorkChunk>> AbstractCounter[] ArrayList<CountString> StringBuilder TreeMap<Integer, Map<Byte, AbstractCounter>> HashSet<AbstractCounter> ByteBuffer ArrayBlockingQueue<Runnable> pidigits long[] Semaphore[] exec[] regexdna Thread[] StringBuffer HashMap<String, String> thread-ring custom ring (also Node[] LinkedList<Node>)