A curated list of notable ETL (extract, transform, load) frameworks, libraries and software. Warning: If you're already familiar with a scripting language, GUI ETL tools are not a good replacement for a well structured application written with a scripting language. These tools lack flexibility and are a good example of the "inner-platform effect". With a large project, you will most likely run into instances where "the tool doesn't do that" and end up implementing something hacky with a script run by the GUI ETL tool. Also, the GUI can conceal complexity and the files these tools generate are impossible to code review. However, the GUI and out-of-the-box functionality can make some tasks simpler, especially for people not comfortable with writing code.