  Superfluid phases of $^3$He discovered in 1972 opened the new area of the
application of topological methods to condensed matter systems. Due to the
multi-component order parameter which characterizes the broken $SO(3)\times
SO(3)\times U(1)$ symmetry in these phases, there are many inhomogeneous
objects -- textures and defects in the order parameter field -- which are
protected by topology and are characterized by topological quantum numbers.
Among them there are quantized vortices, skyrmions and merons, solitons and
vortex sheets, monopoles and boojums, Alice strings, Kibble-Lazarides-Shafi
walls terminated by Alice strings, spin vortices with soliton tails, etc. Most
of them have been experimentally identified and investigated using nuclear
magnetic resonance (NMR) techniquie, and in particular the phase coherent spin
precession discovered in 1984 in $^3$He-B by Borovik-Romanov, Bunkov, Dmitriev
and Mukharskiy in collaboration with Fomin.
