What is TeX - differences between editting and typesetting, TeX inputs and outputs, device independence, pdfTeX
Horizontal/vertical mode, hlist/vlist contents, badness computation during boxing
Multiphase algorithm for breaking paragraph into lines, kinds of demerits, options for choosing paragraph shapes, inefectivity of "looseness" technique
Creating vlist - fixing baselines, panalties genarated during paragraph breaking into lines
Creating hlist - TFM information - inherited kerning, ligatures, "sfcode" table - autospacing
Simplified page breaking algorithm (no floating objects)
TeX variables, grouping, arithmetics of numbers, dimensions and glues
Complete page breaking algorithm
How TeX reads input, "catcode" table
Programming techniques - definitions and conditions
Mathematics and tables
PlainTeX, notes about LaTeX and AMSTeX
We describe the TeX language on the lowest level.