Betacode is a system for transcribing Greek text using Roman letters.  It is extremely useful for writing short passages of Greek in email.  As an example, the Greek word for man, ἄνθρωπος, would be transcribed into betacode as a)/nqrwpoj.

In its original form, the betacode defined by the Thesaurus Linguae Graeca (TLG) research group uses only uppercase Roman letters.  It indicates any Greek capital letters by preceding the Roman capital letter with an asterisk.  As this has proven rather restrictive, a modified betacode is commonly used, where lowercase Roman letters map to lowercase Greek letters, and likewise for uppercase letters.  A lowercase 'j' has also been added to indicate the terminal sigma.

Modified Betacode
BetacodeAlphabet BetacodeAccents
a, A α, Α alpha \ grave accent
b, B β, Β beta / acute accent
g, G γ, Γ gamma = circumflex accent
d, D δ, Δ delta ) smooth breathing
e, E ε, Ε epsilon ( rough breathing
z, Z ζ, Ζ zeta | iota subscript
h, H η, Η eta ", + ϊ diaeresis
q, Q θ, Θ theta <, > macron
i, I ι, Ι iota : · raised dot
k, K κ, Κ kappa
l, L λ, Λ lambda
m, M μ, Μ mu
n, N ν, Ν nu
c, C ξ, Ξ xi
o, O ο, Ο omicron
p, P π, Π pi
r, R ρ, Ρ rho
s, S σ, Σ sigma
j ς terminal sigma
t, T τ, Τ tau
u, U υ, Υ upsilon
f, F φ, Φ phi
x, X χ, Χ chi
y, Y ψ, Ψ psi
w, W ω, Ω omega