Clover is a Java code coverage analysis tool. Key features include per-test code coverage, test optimization (aka selective testing), interactive and historical HTML reporting, IDE integration with Eclipse, IntelliJ IDEA, RAD, and NetBeans. It also works with Ant, Maven, and other command line tools.
Coco is another code coverage utility for Ruby 1.9. One uses it from rspec or unit/test with a simple "require 'coco'". It displays the names of files that are covered less than 90% on the console. It builds a simple HTML report only for files covered less than 90%. It reports sources that have no tests. It is UTF-8 compliant. It is configurable via a simple YAML file. It has colorized console output.