Weka

Library

Java:

• Apache Common - Data Generation
• https://github.com/Devskiller/jfairy - Java fake data generator
• https://github.com/DiUS/java-faker based on Perl: https://metacpan.org/release/Data-Faker
• https://github.com/nomemory/mockneat/wiki/Programatically-populate-MySQL-Schema-with-arbitrary-test-data

Node:

• https://github.com/marak/Faker.js/ - generate massive amounts of realistic fake data in Node.js and the browser