MOSS

Spec sheet

Purpose

MOSS automatically measures program similarity and has primarily been used to detect plagiarism in programming classes.Read 7 Oct 2026 · theory.stanford.edu

Founded

1994Read 28 Sep 2026 · theory.stanford.edu

Commercial use

MOSS is for non-commercial use; the page directs people interested in commercial use to Similix Corporation.Read 7 Oct 2026 · theory.stanford.edu

Community integrations

Community-contributed interfaces and clients include a Node.js package implementing the MOSS socket protocol, AutoMoss web UI, and Nim, Python, OCaml, Common Lisp, Java, and PHP tools.Read 7 Oct 2026 · theory.stanford.edu

Confidentiality

Submitted code appears in results accessible to anyone with the result URL; Stanford says the URL is sent only to the submitter, contains a random integer, and the results directory cannot be browsed or indexed by robots.Read 7 Oct 2026 · theory.stanford.edu

Human review

MOSS identifies similar code but cannot determine why programs are similar, so a person must review highlighted passages before deciding whether plagiarism occurred.Read 7 Oct 2026 · theory.stanford.edu

Languages

It analyzes C, C++, Java, C#, Python, Visual Basic, JavaScript, FORTRAN, ML, Haskell, Lisp, Scheme, Pascal, Modula2, Ada, Perl, TCL, Matlab, VHDL, Verilog, Spice, MIPS assembly, a8086 assembly, and HCL2.Read 7 Oct 2026 · theory.stanford.edu

Results

The service returns HTML pages showing pairs of similar programs and highlights matching passages.Read 7 Oct 2026 · theory.stanford.edu

Retention

Results are typically deleted after 14 days and may be deleted earlier when server disk space is constrained.Read 7 Oct 2026 · theory.stanford.edu

Shared code

MOSS can exclude matches to expected shared code, such as libraries or instructor-supplied code.Read 7 Oct 2026 · theory.stanford.edu

Submission limit

The submission limit is 100 submissions per day per user.Read 7 Oct 2026 · theory.stanford.edu

Support and availability

The page says connection or results delays can indicate server overload and advises users to try again later.Read 7 Oct 2026 · theory.stanford.edu

Who can use it

Anyone may obtain an account by emailing the specified registration message to [email protected].Read 7 Oct 2026 · theory.stanford.edu

Plans and prices

Every MOSS plan and price →

Where Specifiction places it

• Plagiarism Checkers#18 of 317.7
• Plagiarism Detection Software#20 of 287.7