Lambda the Ultimate

Any help with good starter papers in these areas would be appreciated! Prior knowledge would probably be around TAPL level. I'm hoping for papers that are a) primary sources b) clean/modern formalizations or c) provide perspective (or a retrospective). A mixture of b) and c) would probably be ideal :) Realistically, book chapters are less useful than papers, unless they're from a relatively common text (CTM, etc.) or freely available. Talks/slides might be good too.

I have guesses for a couple, but the community here can probably do significantly better and help suggest which makes the most sense for the goal.

1. Dependent Types
- "Simply Easy! (An Implementation of Dependently Typed Lambda Calculus)"
- "Why Dependent Types Matter"
- TAPL 23,25

2. Concatenative languages (pure & typed? impure? optimized?)

3. Concurrency/distribution/communication calculi
- "A calculus of mobile processes"
4. Linear naming / typing

5,6. Modal logic (with an eye to distributed comp.), separation logic (distrib. comp or heap sep.)
- likely papers from CMU :)

Again, any help would be appreciated!

Eight years ago LtU was born. In terms of internet phenomena that is truly remarkable longevity (heck, even google is hardly ten years old), but even in "real world" terms I think this qualifies LtU as a venerable institution.

Ever since Chris posted the first LtU birtday message back in 2001 it has become somewhat of a tradition to post a birthday message each year, and these have become a good place to reflect on the sate of LtU and the direction it is taking. Looking at the previous birthday posts sure got me reflecting. Here they are: year one, year two, year three, year five, year six, and year seven.

So how did we fare this last year? I think that overall we did pretty well, much better than I expected last year when we were in the middle of what looked like a losing battle with spammers. I think we (and by that I mean Anton, first and foremost) managed to pretty much keep spam under control without imposing unnecessary restrictions on new users. LtU was always welcoming to new users, and we strive hard to keep it that way - which leads to the second issue...

We were worried that with too many new members signing up the quality of discussions will go down, and the atmosphere of the site will change. While this happened to some extent from time to time, I think that in general most discussions remain as informative as ever - in fact, some have become too highbrow even for me... Quite a few new members have become regulars, and even contributing editors. I am very glad to see this happen, for all the obvious reasons. I am especially glad to see that we stopped attracting so many "drive-by members" who sign up only to ask one question and are then gone. LtU is not the best place for such questions, which in the past also proved to be mostly off-topic. New members, on the other hand, always add something new to the community.

Indeed, what is truly phenomenal and inspiring about LtU for me is not the continuity of the site, but the continuity of the community. I've been saying this every year, I think, but it is worth repeating. What gives LtU its unique flavor are the many members that have been part of the community for many years, some from the very early days. While not an online sewing circle, I think LtU does encourage long time members to become contributing editors, to share their interests more explicitly, and even to mention from time to time, if they so wish, their own changing circumstances. This is a professional community, but a community none the less.

The community is what holds LtU together, but it is hidden in the forum. The public face of LtU, and what should be the main focus of the discussion on the site, are the home page news items. From the early days there has been a tension between the forum and the blog aspects of LtU: while ideally all good links should be on the home page, and these should be the focus of discussion, quite often the forum takes on a life of its own. Since some members do not follow the forum discussions closely, and since the home page items are a good way to stir the direction of the site, this may be less the ideal. The solution, as always, is for the contributing editors (who are those members who manage the home page group blog) to be more active, and for more members to become contributing editors. If you are a regular, and think that you can contribute semi-regularly (i.e., as often as you want) to one or more of the LtU departments, you should consider signing up.

Let me conclude this rambling message on a more personal note. This year I moved to Menlo Park, California. Hearing from and meeting local LtU members made the move easier. It was a great experience to encounter people in various places who recognized my name, and asked "Are you the guy from LtU?" (the next question usually being "So what do you say about Scala?", by the way). Being extremely busy I didn't take advantage of all the activities around here this year, but the one time I did manage to go to a BayFP meeting was great fun.

Who knows what the next year will bring? For now, thank you all for your participation. You are LtU!

I've written an overview of the different representations used in garbage collection based on my readings and the great explanations Andreas provided in another thread.

I'm certainly going to make good use of this information, and hopefully it will be useful to someone else too. I'd appreciate any corrections!

[Edit: I also describe another pointer tagging scheme that I haven't come across in the literature. If anyone has seem something similar, or you think it's unworkable in practice, I'd love to hear about it!]