All data is available for free download. Use the [Download] buttons on the data pages. Files can be quite large (up to several hundred megabytes), so make sure to only download what you need.
All downloads are compressed in zip archives.
Updated data is usally available once a day. Some data is updated less often if it doesn't change much. You can use automation to re-download new versions of the data, but please use the If-Modified-Since header. This will make sure that data is only downloaded if it actually changed.
Use the curl program for downloading, it supports the -z, --time-cond option. You can set it up easily so that it will only re-download a file if it has changed.
If you abuse this service and download the date more often than necessary, we might suspend the service without notice!