A variety of text and source code editors are available for both X-windows and text terminals.
Pico [Helix] [Biowulf]
Pico is a simple, user-friendly text editor derived from the editor in the Pine email client. Type pico [filename] to edit a file and use the key commands listed at the bottom of the screen to access various functions.
Emacs [Helix] [Biowulf]
Emacs is a text and source code editor for text terminals and X. It has a vast set of features and is well suited for doing everything from reading mail and simple text editing to managing and editing large programming projects. It has its own help and tutorial which can be accessed by typing Ctrl-h i and Ctrl-h t respectively. Type emacs [filename] to edit a file. For more info, see here.
ESS [Helix] [Biowulf]
Emacs Speaks Statistics is an Emacs mode for interactive statistical programming and data analysis. Languages supported: the S family (S, S-PLUS and R), SAS, BUGS/JAGS, Stata and XLispStat. Putting the line (load "/usr/local/share/emacs/site-lisp/ess-5.13/lisp/ess-site") in your .emacs file will make an *ESS* buffer available. For more info, see here.
NEdit is an GUI style editor for plain text and source code files. It provides mouse based editing and a streamlined editing style, based on popular Macintosh and MS Windows editors, using the X-window system. NEdit requires an X-based workstation or X-Terminal. Type nedit [filename] to edit a file.
SciTE (3.2.5) [Helix] [Biowulf]
SciTE is a source code editor for X-windows that is well suited for scripting and programming small projects. Type SciTE [filename] to edit a file.
vi [Helix] [Biowulf]
The venerable vi editor is a text and source code editor for text terminals and X-windows. It has a large set of features for simple text editing and for sophisticated programming projects. Type vi [filename] to edit a file. Type :help to start learning vi.
vim [Helix] [Biowulf]
vim is a text editor that is upwards compatible to Vi. It can be used to edit all kinds of plain text. It is especially useful for editing programs with syntactical coloring. There are a lot of enhancements above Vi: multi level undo, multi win- dows and buffers, syntax highlighting, command line editing, filename completion, on-line help, visual selection, etc..