Motivations:

• There are several commercial tax software packages, but they are not available for every platform. The open-source package can be used on all platforms, including Linux and Unix.
• As a tax-payer, we expect to understand how our tax is determined. Neither the government's forms, nor the commercial tax preparation packages reveal, in a clear way, the tax equations and the rules used. (As a programmer, I wish to see the unambiguous expressions or code. Consider this Fed-1040-For-Programmers.)
• Revealing the tax-law in concise -easily executable- form enables us to better understand tax consequences of our decisions throughout the year; not just at tax-time.
• The commercial software packages have become invasive. They ask questions which do not seem to affect our tax. On electronic submission, or even paper forms, we have little visibility as to what information was used or passed.
• Commercial software packages have become bloated - often requiring the installation of other packages we may not otherwise wish to do, such as IE7, etc.. These installations may be disruptive of our other software, perhaps breaking other things on our systems, merely for the purpose of, for example, adding video tax-wizards, etc..
• The commercial tax packages are awkward. Let's call the "tax-interview" method "20,000" questions. Partially this is a tribute to the complexity of our tax code itself, and all the special cases therein. (For example, I live in a city and I'm tired of TurboTax asking how many chickens and tractors we have!) If you accidentally err in making an entry, they sometimes drop into a mode which they never get out of (ex. foreign tax). Instead, a simple one or two page form, that can be easily traversed and edited with your favorite text-editor, offers many advantages, including the ability to view and print a concise snapshot of your numbers, quick revisions, what-ifs, etc..
• Many of us have written our own "ad-hoc" tax programs, which need to be re-written each year as the tax code changes, etc.. Spreadsheets don't really do, as the number of entries for a given category often changes, and they cannot handle all the conditional calculations required in taxes. It would be preferable if there were a common substrate of routines which would be stable, but which could be used to quickly describe new tax rules.
• By sharing an open-source tax-program, we might all benefit by gaining a more complete and correct package.
• Keep the tax-package simple by being a basic text-oriented program; no graphical interface complexity. Require only rudimentary knowledge to understand/modify the code. (This should not preclude anyone from adding a GUI shell to access it, or incorporating a GUI later. Hint.)