We study, from a quite general point of view, the family of all extensions of a positive hermitian linear functional $$\omega $$
ω
, defined on a dense *-subalgebra $${\mathfrak {A}}_0$$
A
0
of a topological *-algebra $${\mathfrak {A}}[\tau ]$$
A
[
τ
]
, with the aim of finding extensions that behave regularly. The sole constraint the extensions we are dealing with are required to satisfy is that their domain is a subspace of $$\overline{G(\omega )}$$
G
(
ω
)
¯
, the closure of the graph of $$\omega $$
ω
(these are the so-called slight extensions). The main results are two. The first is having characterized those elements of $${\mathfrak {A}}$$
A
for which we can find a positive hermitian slight extension of $$\omega $$
ω
, giving the range of the possible values that the extension may assume on these elements; the second one is proving the existence of maximal positive hermitian slight extensions. We show as it is possible to apply these results in several contexts: Riemann integral, Infinite sums, and Dirac Delta.