This open source repository contains the standard QL libraries and queries that power [LGTM](https://lgtm.com), and the other products that [Semmle](https://semmle.com) makes available to its customers worldwide.
There is [extensive documentation](https://help.semmle.com/QL/learn-ql/) on getting started with writing QL.
You can use the [interactive query console](https://lgtm.com/help/lgtm/using-query-console) on LGTM.com or the [QL for Eclipse](https://lgtm.com/help/lgtm/running-queries-ide) plugin to try out your queries on any open-source project that's currently being analyzed.
We welcome contributions to our standard library and standard checks. Do you have an idea for a new check, or how to improve an existing query? Then please go ahead and open a pull request! Before you do, though, please take the time to read our [contributing guidelines](CONTRIBUTING.md). You can also consult our [style guides](https://github.com/Semmle/ql/tree/master/docs) to learn how to format your QL for consistency and clarity, how to write query metadata, and how to write query help documentation for your query.