Update README with more background info

Author: samuell

README.md

@@ -2,12 +2,23 @@ RDF2SMW
 =======
 
 A tool to convert from RDF triples to Semantic MediaWiki facts (in MediaWiki
-XML export format)
+XML export format).
+
+It allows you too import RDF data into a Semantic MediaWiki, via MediaWiki's
+robust built-in XML import feature.
 
 RDF2SMW is based on the [FlowBase](https://github.com/flowbase/flowbase)
 flow-based programming micro-framework.
 
-**Status:** Basic MediaWiki import XML now works. Work is being done on more features and fixing bugs.
+RDF2SMW is very similar to the RDF import function in the
+[RDFIO](https://github.com/rdfio/RDFIO) Semantic MediaWiki extension, but takes
+another approach: Whereas RDFIO converts RDF to wiki pages and imports them in
+the same go, RDF2SMW first converts RDF to an XML file outside of PHP (for
+better performance), and then importing using MediaWiki's built-in import
+function.
+
+**Status:** Basic MediaWiki XML generation now works. Work is being done on
+more features and fixing bugs.
 
 For more detailed status, see [TODO.md](https://github.com/samuell/rdf2smw/blob/master/TODO.md)