Various notes and resources
Mirror symmetry workshops notes
MSRI videos
MathOverflow
The Stacks Project
Atiyah 80
nLab
U of Chicago Geometric Langlands seminar page
- Kontsevich's 1998 course at ENS (in French)
- Letter from Kontsevich to Beilinson
David Ben-Zvi's Geometric Langlands page
UT Austin notes/videos from "Perspectives in Geometry" lecture series
Segal's notes (1999) on TFT, QFT, quantization
Deformation theory notes from a course (1994) by Kontsevich
Deformation theory, volume 1 book by Kontsevich and Soibelman
Gromov-Witten theory notes from a course (1997) by Givental
- a mirror
- Spring 2003 notes
Daniel Murfet's notes on algebraic geometry, commutative algebra, categories, etc
Milne's course notes on algebraic geometry, number theory, etc
Notes and other materials from 1996-1997 IAS program on QFT
Anton Geraschenko's notes from various Berkeley courses
Notes from Berkeley QFT supersemester (Fall 2007)
Talbot workshop notes/references/etc
EGA, SGA, FGA
Sheel Ganatra's notes
Aaron Smith's notes
Gabriel C. Drummond-Cole's notes
SFT workshops
NUMDAM
Hartshorne notes on deformation theory

Math blogs and other stuff
Berkeley math dept
Berkeley physics theory seminars
Rigorous Trivialities
This Week's Finds in Mathematical Physics
The n-Category Cafe
Secret Blogging Seminar