DMOJ vs TAO

DMOJ is an open-source platform for programming contests and an archive of programming problems. Its archive includes tasks from past CCC, CCO, COCI, IOI and JOI competitions, among other sources, and it runs a monthly open programming competition. Public contests can be hosted at no cost. Contest formats include ICPC, IOI, AtCoder and ECOO, with system testing, hidden scoreboards and virtual participation. Judging supports interactive and signature-graded tasks, runtime data generators, custom output validators, per-language resource limits and scaling to hundreds of judging servers. Problem statements can include Markdown, LaTeX math and figures, syntax highlighting, PDF generation and built-in editorials. DMOJ integrates with Stanford MOSS for plagiarism checking and supports OAuth login, two-factor authentication and fine-grained staff permissions. Documentation is available for self-hosting the site and judge; the installation guide says the site is tested with MySQL and is unlikely to work with other databases. AI use is prohibited in rated contests, and judging resources cannot be used for AI training.

TAO is an online platform for creating, delivering and managing digital assessments. Authors can build tests manually, convert existing exam files, use AI-assisted drafting or import QTI packages. Question formats include Choice, Extended Text, File Upload, Hotspot and Text Entry. Scoring supports automatic and manual methods, partial credit, weighted responses and cut scores, with branching logic also available. Results can be reviewed through session and test-taker reports, custom reports, CSV results, Data Explorer and TAO Insights. TAO supports QTI 2.2 and QTI 3.0, and promotes interoperability through QTI and LTI. Delivery options include online, LMS via LTI, test centers, local proctoring, and cloud-hosted or self-hosted configurations. TAO Cloud offers shared or private hosting using providers including AWS, Google Cloud and Linode. Starter is free for one author and 50 learner attempts monthly; Community Edition is a free, self-hosted open-source option. Paid plans include TAO Author at $149 a month and TAO Ignite at $990 a month; custom plans are also listed.