I believe OptionStar downloads options chains for stocks/indexes from multiple exchanges -- free, 20-minute delay. OptionStar also downloads futures contracts data (end-of-day, free) but does it download futures option chains too? Does Hoadley's software actually download option chains? The website seems to imply that underlying data is downloaded and option values are calculated (theoretical) but not downloaded? Anyone know?
The Hoadley software provides an add-in for Excel. Once you have installed the add-in, you have access to various functions that compute historic volatility, implied volatility, etc. from a set of data. Some of the functions automatically access Yahoo data (and perhaps other data) for free. If you have a subscription to one of their integrated data feeds (search for "sources of data" on http://hoadley.net/options/strategymodel.htm), you can load the options chains that the particular provider provides. The data can stream to your Excel file and you can use the built in functions to generate various values. The package comes with some sample spreadsheets but you can use the built-in Hoadley functions to configure a spreadsheet to meet your own needs. MS
OptionStar has a Futures version as part of the program. The free data retreaval in OS is easier than in Hoadley in that it is automatic. In Hoadley you have to chose from a list of the sources and it seems to default to the wrong one if you don't. The two programs have a different range of capabilities, It is best to experience them first hand. They are both downloadable for free trial.