...is compactness. We had dinner with some new friends last night, one of whom bailed out at MA in his pursuit of English because the job prospects for Ph.D. seemed grim. Now he writes software. Confronted with a mirror into my own unique combination of interests, I started thinking about what lines of code and lines of poetry have in common, and what might attract me to both.
Both require precision, and poetry usually also involves some degree of linguistic compactness. Also, just as software executes within the context of an operating system, poetry likewise "executes" within the psyche of the reader. A few lines in either form can have a profound impact, sending memory pointers in myriad directions.
While it is the context within which either form executes that largely determines the result, even the slightest adjustments in either form can have a significant effect. Subtlety, clarity, and intimacy with the language are all required traits that get amplified through the power of each discipline.