Given enough time, storage, and processing power, Osmosis allows you to extract, adapt, and store OpenStreetMap data in more or less any way you can imagine. If you are working with OpenStreetMap data in country-sized quantities or larger, it should be one of the first tools you use to get the information you want from the raw data.
You should now know how to perform the following tasks with Osmosis:
Read data from a planet file or a pre-built extract.
Read data directly from the OpenStreetMap API or XAPI
Write processed data to a file or database
Cut out an area of data using a bounding box or a bounding polygon
Extract a subset of features from a dataset using tag filters
Keep your source of data up-to-date using replication
If you use large amounts of OpenStreetMap data in an application or to create a map, eventually you will encounter problems that can only realistically be solved using Osmosis. For this reason, it's worth getting to know how Osmosis works, what it's capable of, and...