UC Irvine Machine Learning Repository
archive.ics.uci.edu/ml/
We currently maintain 432 data sets as a service to the machine learning community. You may view all data sets through our searchable interface.

Parsec
http://parsec.cs.princeton.edu/
The Princeton Application Repository for Shared-Memory Computers (PARSEC) is a benchmark suite composed of multithreaded programs. The suite focuses on emerging workloads and was designed to be representative of next-generation shared-memory programs for chip-multiprocessors.

SPEC INT
https://www.spec.org/benchmarks.html
The diverse and actively maintained benchmark suite provided by the Standard Performance Evaluation Corporation.

Artifact Evaluation
http://crest.cs.ucl.ac.uk/autotransplantation/downloads/artifact.html
As accepted by the ISSTA 2015 Artifact Evaluation track, this contains the tool ╬╝Scalpel, which was used for autotransplantation. Also we provide our regression, augmented regression, and acceptance test suites, where possible.

Automated program repair and bug repositories
http://repairbenchmarks.cs.umass.edu/
http://program-repair.org/benchmarks.html
http://groups.csail.mit.edu/pac/patchgen/

General Program Synthesis Benchmark Suite
thelmuth.github.io/GECCO_2015_Benchmarks_Materials/
We present a suite of 29 general program synthesis benchmark problems systematically selected from sources of introductory computer science problems. This suite is suitable for experiments with any program synthesis system driven by input/output examples. We present results from illustrative experiments using our reference implementation of the problems in the PushGP genetic programming system. The results show that the problems in the suite vary in difficulty and can be useful for assessing the capabilities of a program synthesis system.
This site is based on a 2015 archive.

GP Benchmarks
www.gpbenchmarks.org/
www.gpbenchmarks.org/wiki/
This site is the home for a community-led effort towards improving experimentation in Genetic Programming (GP).

This site is not actively maintained, but contains good resources.