XML becomes the de-facto standard for exchanging and presenting information on the Web. However, XML data is also recognized as verbose, since it heavily expands the size of the data with repeated tags and structures. The data verbosity problem gives rise to many challenges of query processing and data exchange. The hindrance is more apparent in bandwidth- and memory-limited devices. Compression techniques are the important way to overcome the verbosity problem. The XMill takes the advantage of awareness of XML, so it makes XMill as efficient tool for compressing the XML data.