wikipedia: FASTQ format
http://nar.oxfordjournals.org/content/early/2009/12/16/nar.gkp1137.full

FASTQ format is a text-based format for storing both a biological sequence (usually nucleotide sequence) and its corresponding quality scores. Both the sequence letter and quality score are encoded with a single ASCII character for brevity. It was originally developed at the Wellcome Trust Sanger Institute to bundle a FASTA sequence and its quality data, but has recently become the de facto standard for storing the output of high throughput sequencing instruments such as the Illumina Genome Analyzer

• text based
• no standard file extension

• nucleic acid sequences