  In these notes we revisit the tachyon lagrangian in the open string field
theory using background independent approach of Witten from 1992. We claim that
the tree level lagrangian (up to second order in derivatives and modulo some
class of field redefinitions) is given by $L = e^{-T} (\partial T)^2 +
(1+T)e^{-T}$. Upon obvious change of variables this leads to the potential
energy $-\phi^2 \log {\phi^2 \over e}$ with canonical kinetic term. This
lagrangian may be also obtained from the effective tachyon lagrangian of the
p-adic strings in the limit $p\to 1$. Applications to the problem of tachyon
condensation are discussed.
