Software:

Texts:

- planet math
- polymath blog,
- Wikipedia's list of mathematical topics,
- Open source math books on this site
- math bookshelf at project gutenberg (public domain texts)
- math at the wikiuniversity

Papers:

- Math Preprints (arXivs)
- Electronic Library of Math (ELibM)
- online theses in number theory
- online theses database.
- plos.org, the Public Library Of Science (no math journals yet)
- Directory of Open Access (Math) Journals

General open education/knowledge links:

- The Open Knowledge Definition
- open source definition
- Open textbooks
- Open-source texts from the late David Santos: here and here.
- Open-source texts from William Trench: here
- public domain texts at archive.org
- Open Educational Resources site has a

math and statistics section

(see also their textbooks section), with widely varying levels. - Coursera
- MIT OpenCourseWare
- Connexions
- Saylor
- Khan Academy
- a list of over 500 free online university courses from opencoulture
- a site cataloging online courses.

Links:

- Open source math papers, books and math tables on this site
- OpenScience blog with pages of links

to "open source" science software (which may or may not be open source in the sense of OSI). - textbook revolution
- online math texts (Univ. Penn. library)
- open source books (very small math selection)
- open source blog of Glyn Moody (technology journalist)
- free math texts
- free algebra text download
- free algebraic function text download
- free decimal arithmetic text download
- free software foundation
- creative commons licenses
- website for toric (GAP package)
- guava (GAP package)
- (very) small groups
- slashdot science news.