Open Tax Solver (OTS) is an open source, easy-to-use, cross-platform, simple and free graphical software implemented in C and designed from the offset to be used for calculating Tax Form entries, refund-due, as well as tax-owed for State or Federal personal income taxes.

The application is packed with many forms, including the ones for Scheds A, B, C, D, L, US 1040, as well as forms for several states. The software lets users to easily compute taxes and edit tax information. An optional command-line interface is also provided.

Its graphical user interface (GUI) is as simple and intuitive as possible. It features no menus or toolbar, just a single, resizable dialog that asks users to select a tax program (US 1040 (with Scheds A, B, D), USD 1040 Sched C, US 8829, CA State 540, NC State DC400, NJ State 1040, OH State IT1040, PA State 40, VA State 760, NY State IT201, MA State 1 or other), as well as to open a tax file or template.

The Open Tax Solver software is written entirely in the C programming language, using the GTK+ GUI toolkit for its graphical user interface. It is engineered to run on GNU/Linux, Microsoft Windows and Mac OS X operating systems.

For your convenience, the software is distributed as pre-built binaries for 64-bit and 32-bit instruction set architectures, which can be used without installation on any distribution of Linux. The project’s source code is distributed on Subversion.

To use the application, simply download the binary package that corresponds to your computer’s architecture (64-bit or 32-bit), save the archive somewhere on your computer, extract it, open the extracted folder and double-click on the ‘Run_taxsolve_GUI’ executable. To build taxsolve packages, double-click on the Build_taxsolve_packages_LINUX.sh script.