DMOJ vs Gradescope

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.

Gradescope is an assessment platform for instructors who administer and grade work completed online or in class. It handles variable-length assignments, including problem sets and projects, as well as fixed-format worksheets, quizzes, bubble sheets, and exams. Instructors can grade with flexible rubrics, provide detailed feedback, and revise rubric decisions on work that has already been graded. For programming work, students can submit code from GitHub or Bitbucket; instructors can use autograders or add inline comments during manual grading. Gradescope also offers question- and rubric-level statistics, with grade and data exports. Its AI can group similar responses for instructor review on some question types; Answer Groups and AI-assisted grading require an Institutional license. That license also enables integrations with Blackboard, Brightspace, Canvas, Moodle, and Sakai. Without it, rosters can be imported by CSV and grades downloaded for LMS upload. The free Basic plan is listed at free. Android and iOS apps support student submissions and grade viewing, not instructor workflows.