IVOA - International Virtual Observatory Alliance

IVOA Documents - VO standards are there

US NVO,VO India

VO Services, A list of Webservices

CDS, CDS Webservices

PLASTIC - PLatform for AStronomical Tool InterConnection is a communication protocol for client-side virtual observatory tools.

Carnivore - the open source VO Registry

HTM - Hierarchical Triangular Mesh

Q3C - Indexing the sky with PostgreSQL, download from sourceforge.

HealPix - Hierarchical Equal Area isoLatitude Pixelization of the sphere

Igloo - exact azimuthal pixelization

The Quadrilateralized Spherical Cube and Quad-Tree For All Sky Data - paper by White, Richard A.; Stemwedel, Sally W.

Aladin - an interactive software sky atlas

Topcat - an interactive graphical viewer and editor for tabular data

VOPlot - a tool for visualizing astronomical data

VOStat - Statistical analysis for the Virtual Observatory

TERAPIX software - SExtractor,SkyMaker and more.

Datascope - Query VO resources for a given region of a sky