# What features does q /KDB provide for HFT use?

It appears q/KDB is being using for Time series analysis for HFT. What are some of the advantages of using q/KDB for HFT time series over other regular time series.

Does it provide for multivariate statistical testing etc done normally on time series?

Does it provide easy to use facilities for Statistical Arb and technical analysis?

Are there any free versions of q/KDB to use and learn?