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It fixes a few problems that were discovered after the release of Groovy 1.5.0. In particular: a dead lock in the Groovy classloader, and a problem with input streams with the Ant builder.
Also, a problem in highly concurrent setups on multi-processor machines made Groovy run anormally slowly, and this new release also fixes this problem and makes Groovy run much faster using the full power of all the CPUs.
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