  Context. Solar observatories are providing the world-wide community with a
wealth of data, covering large time ranges, multiple viewpoints, and returning
large amounts of data. In particular, the large volume of SDO data presents
challenges: it is available only from a few repositories, and full-disk,
full-cadence data for reasonable durations of scientific interest are difficult
to download practically due to their size and download data rates available to
most users. From a scientist's perspective this poses three problems:
accessing, browsing and finding interesting data as efficiently as possible.
  Aims. To address these challenges, we have developed JHelioviewer, a
visualisation tool for solar data based on the JPEG2000 compression standard
and part of the open source ESA/NASA Helioviewer Project. Since the first
release of JHelioviewer, the scientific functionality of the software has been
extended significantly, and the objective of this paper is to highlight these
improvements.
  Methods. The JPEG2000 standard offers useful new features that facilitate the
dissemination and analysis of high-resolution image data and offers a solution
to the challenge of efficiently browsing petabyte-scale image archives. The
JHelioviewer software is open source, platform independent and extendable via a
plug-in architecture.
  Results. With JHelioviewer, users can visualise the Sun for any time period
between September 1991 and today. They can perform basic image processing in
real time, track features on the Sun and interactively overlay magnetic field
extrapolations. The software integrates solar event data and a time line
display. As a first step towards supporting science planning of the upcoming
Solar Orbiter mission, JHelioviewer offers a virtual camera model that enables
users to set the vantage point to the location of a spacecraft or celestial
body at any given time.
