  The advent of all-sky facilities, such as the Neil Gehrels Swift observatory,
the All Sky Automated Search for Supernovae (ASASSN), eROSITA and Gaia has led
to a new appreciation of the importance of transient sources in solving
outstanding astrophysical questions. Identification and catalogue
cross-matching of transients has been eased over the last two decades by the
Virtual Observatory but we still lack a client capable of providing a seamless,
self-consistent, analysis of all observations made of a particular object by
current and historical facilities. HILIGT is a web-based interface which polls
individual servers written for XMM-Newton, INTEGRAL and other missions, to find
the fluxes, or upper limits, from all observations made of a given target.
These measurements are displayed as a table or a time series plot, which may be
downloaded in a variety of formats. HILIGT currently works with data from X-ray
and Gamma-ray observatories.
