What XBSDB is
XBSDB is the JavaScript database library to operate with data arrays in JavaScript code like with SQL-data.

What XBSDB does
XBSDB stores, arranges and selects data in your scripts. You can insert, delete, update and select records, you can use indexes to make the selection faster. JSON-based methods allow you to prepare data at one side (browser or web-server) and to load them on other one (web-server or browser).
Using XBSDB allows to move some database operations from web-server to client machine and to reduce number of web-server requests.

Main XBSDB feature
The main feature of XBSDB is the speed of 'select' operation by complex WHERE-condition. XBSDB parses WHERE-expression to simple conditions tree only once, then this tree is used to reduce numbers of records to process per each condition. Indexes also help to reduce numbers of records to process.

What XBSDB consists of
XBSDB consists of 2 parts - for browser and for web-server. Browser part is the core, web-server part just prepares data for exchange. Browser part is JavaScript code, web-server part is presented in 2 equivalent variants in Perl and PHP.