Hi, Steven.

>I have a 3-tier application that pass data between the layers with XML. It can run on DCOM or on HTTP over the internet. The problem with running it on the internet is bandwidth. XML is not that efficient on large sets of data, so I would like to compress it before I send it.
>
>Does anyone know of any good utility to compress XML? If it is not free, and I have to pay for it, that is OK.
>
>The functionality I am looking for:
>1) Preferably compresses memory variables without having to write to files, such as
>lcCompressedData = oUtility.compress(lcUnCompressedData)
>lcUnCompressedData = oUtility.unCompress(lcCompressedData)
>2) Should be easy to distribute in applications. Preferably should be just one COM DLL.

In a DCOM environment over a LAN, and if you're keeping the result sets moderately small, you shouldn't have any problem. When sending XML over HTTP you have to take in consideration that HTTP already compresses the stream, and it is very efficient with XML as it is -not coincidentally- another SGML variant, very similar to HTML. HTTP is very good with tagged and ascii data. If you need to pack binary information within the messages, you might need some kind of extra compression. If you don't, I won't add anything else in most cases.

Hope this helps,