1. A computer-implemented method in a client computing system for synchronizing content of a file with a distinct and separate server computing system, comprising: in the client computing system, dividing the file into a plurality of portions based on a chunking algorithm; by performing an index lookup into a local data content index on the client computing system, and without querying the server computing system to find out what data content is already present on the server computing system, determining which of the plurality of portions of the file correspond to data content deemed to be already present on the server computing system, wherein the local data content index resides on the client computing system and indexes the data content of a plurality of files of the client computing system; generating a patch based on the plurality of portions of the file, the patch comprising a plurality of segments, each segment corresponding to a portion of the plurality of portions of the file, each segment either containing data content or a reference to data content the reference to data content comprising information for locating the corresponding data content on the server computing system, the segment containing data content when the corresponding portion of the file is determined to correspond to data content not deemed to be already present on the server computing system, the segment containing a reference to data content when the corresponding portion of the file is determined to correspond to data content deemed to be already present on the server computing system; forwarding the generated patch and causing the file to be generated on the server computing system from the patch in conjunction with data content already present on the server computing system, thereby synchronizing the content of the file without forwarding the entire data content of the file; wherein the file is generated by: for segments of the patch containing data content, appending the contained data content to the generated file; and for segments of the patch containing a reference to data content, copying the referred to data content from the data content already present on the server computing system and appending the copied data content to the generated file.