17. The method of claim 10 wherein said receiving into said source parser said textual source file comprises: receiving at least one textual source file into said source parser responsive to a command-line command.
10. A method for automatically generating updated sequence diagrams for communications protocol transactions in response to user changes to sequence diagram source data, the method comprising: in a computer: loading a textual source file into an intermediate variable and displaying content of the intermediate variable in a graphical user interface as editable text, wherein said textual source file is in non-proprietary language and describes a flow for a communications protocol generated by a software application; building, by a source parser executed by the computer and based upon said intermediate variable, a data model for a diagram of said flow described by said textual source file; generating, by a diagram parser executed by the computer and based on said data model, corresponding drawing commands; responsive to said drawing commands, rendering by a rendering engine executed by the computer a sequence diagram representing said flow described by said intermediate variable as editable text, wherein the sequence diagram includes a graphical representation of a series of transactions between two or more actors, wherein the actors comprise entities that exchange message packets in communications protocol transactions and wherein: each of the two or more actors is represented by a vertical line; time is represented by a vertical progression down the vertical lines; transactions are represented by message packets exchanged between the two or more actors; and message packets are represented by directional horizontal lines between the vertical lines of actors and a label corresponding to each directional horizontal line denotes the message packet being transmitted; allowing a user to edit said content of said intermediate variable via said graphical user interface; and generating, by said diagram parser and based upon said edited content of said intermediate variable, an updated sequence diagram reflecting a change made by said user.