[_CD8_]<cedardocs>PE2>Report>pe2.4b!1

All the people listed at the beginning of the report are candidates for participation in the actual EPE effort, and most of them have indicated a willingness to contribute in some way regardless of whether a Lisp or Mesa base is chosen. However, nearly all of these people have substantially more experience in one of the two languages than in the other. To achieve our goals, it is essential that people with both kinds of experience participate in the project in a major way: we are very concerned that if a Mesa base is chosen, people with Lisp backgrounds might not feel highly motivated to contribute their unique experiences and insights to the project, and conversely if Lisp is chosen.

The following are individual responses to a message we sent out to everyone who had indicated an interest in the programming environment area by putting themselves on an on-line distribution list. The absence of someone from the following list does not mean they are not interested in working on EPE.

I would probably be interested in low-level work in EPE (i.e. the parts which might be considered as an operating system), and in at least keeping track of language design.

I cannot participate in actual implementation design or coding. I guess that puts me in the class of kibitzers. However I have several ideas on programming languages and programming environments that I would like to share. (Most of these ideas came out of the LISP70 project that Enea, Tesler and I did at Stanford.) I am anxious for EPE to succeed because PARC is not currently at the state-of-the-art in programming environments. In the short term, some simple extensions would benefit us all (such as Lampson’s and Levin’s intermediate Mesa PE ideas). But in the longer term, I hope EPE turns out to be a laboratory for basic research into programming languages and techniques. I think there’s at least a 5-10 year project waiting there.

I expect to spend about half my time on EPE through mid-1979. What happens after that depends a lot on how well we are doing at genuinely incorporating the strengths of all three languages into a single system. If things are going well, I expect EPE to continue as my largest single interest for at least another year after that.

I am interested in the tradeoffs between protection mechanisms and type systems for builing layered systems; I am especially interested in the design of a flexible protection scheme for the D* machines that would enable the construction and debugging of large systems. This interest also encompasses hardware/microcode support for a run time type system. I strongly favor Mesa over Lisp as the EPE base.

I plan to spend the first part of January reviewing the EPE material in detail. It may be possbile to view part of my work in the comming year as EPE related, or my work as part of the EPE project, or both; it depends on the intersection of my thesis interests with EPE needs.

My motivation is twofold: to have a friendly environment in which to do my own research, and to make sure certain fundamental facilities are provided at an acceptable level of quality.

My time commitment would depend heavily on my research interests and the congeniality of epe to my working style. For example, a very important attribute for me is consciseness of notation. Has it been a serious epe desideratum?

With regard to base language choice, my deep-down feeling is that a lisp based environment would be infinitely more appealing to me than a mesa based one.

I consider myself committed to EPE as my major technical effort for the next couple of years, independent of starting point. My background implies that my contribution to early phases of the project will depend on the starting point: with Lisp, I would expect to contribute to requirements definition; with Mesa, I could get involved in the system programming.

I expect the EPE to be my major research interest for the next 18 months. There is some chance that I will change my mind about this if Lisp is the base. I expect to be able to spend a lot of time on design, but am less optimistic about begin able to do any substantial programming jobs.

I consider that, if EPE is Mesa-based, I will consider it my second-priority project (after the distributed transport mechanism). That translates to about 30% of my time over the next year. After that, I can’t say. I would expect my involvement with EPE to be greatest during the earlier phases, when fundamental structures are being built. I probably couldn’t contribute much to a Lisp-based EPE.

I plan (if I am hired by CSL) to devote full time to EPE starting July 1 working on those pieces of system which are prerequisite to building Masterscope-like facilities for Mesa. I imagine that actually getting to actual Masterscope facilities will be in the rather distant future: working on either an S-expression representation (easier to analyze), data base facilities (shared data base server), access to remote files, etc. will take first priority.

I might sign up to work on the design and implementation of a more powerful static checker for the language. I guess about half-time would be my level of commitment.

If Mesa is chosen as the base for CSL’s EPE, the implications for SD will be carefully considered. We have no current position on the numerous policy questions that would be raised by direct participation, but contributions to subprojects of mutual interest seem likely to the extent that SD’s goals and schedules permit.

My principal interests re the EPE issues are (a) designing a "strong" but much more flexible type system, (b) (for Mesa) designing a safe language subset and storage reclamation techniques, (c) implementation of (a) and (b).

Database:
There are two issues concerning database in EPE. One is the database for interaction, namely masterscope level thing. I would like my database system to be considered for the use in EPE system along ASD and masterscope. I will demonstrate the system tomorrow so many of you may have a chance to evaluate. The other is the access from the programmers. This may be some type extension and packages. If the previous line is chosen I will spend quite a few time of mine devoting bringing up the user interface. If not I will be interested in the latter subject which I would be interested in spending some of my time.

Basic microcode:
I am willing to support Dorado Mesa and its extension. Birrel may want to do this in connection with Pilot. In that case I am willing to help him.

Compiler, etc.:
I have quite a few experience in writing compilers. But there are so many people who can do it, so unless there is some urgent need I may not particularly want to do it.

I’m willing to play a substantial role in what you’ve called the Tools segment of the EPE project. I cannot in all honesty call it my primary activity, however, since it seems extremely important to further the voice communications work. Percentages are probably misleading, but I’d expect to devote 30-50% of my time to it. Goals: unified (default) approach to user interface for program development, control of applications.

I expect to spend a majority of my time on the Laurel transport project during the next 6 to 9 months, so I can commit only a fraction (say, 25%) until that is done, but perhaps more later (50 to 75%).

As for what I might do: if the EPE is Lisp-based, one obvious task would be to implement a Pup package. If it is Mesa, I am less certain what to do, though one possibility is to extend the file system to access IFS or Juniper remotely. I am also prepared to contribute effort in whatever other ways seem appropriate, e.g., writing Dorado microcode. Since I am not familiar with the insides of either Lisp or Mesa, and I am only superficially familiar with Lisp as a whole, it is probably not appropriate for me to work on the basic kernel of EPE.

I expect significant portions of my time will be involved in epe, regardless of which base they start from. If mesa, then would be in implementing various user level packages not in mesa, such as programmer assistant, file package, dwim type stuff, etc. If starting from lisp, I have a less clear picture of what I would be doing, at least initially, since a lot of things have to be changed down in the guts of lisp, but I would think I would be fairly involved simply because I am currently custodian of so much of the system, and can also make inputs about how various changes will affect the style of lisp programming.