You are making four big mistakes:

First you are angry. You are not so much attacking PL/I as attacking me personally.

Second you are pursuing religious arguments about programming languages.

Third you are arguing things about PL/I that are really not part of the language.

Fourth much of what you say about PL/I is technically wrong.

"PL/I compilers are awful".

What PL/I compilers are awful? As far as I know, there aren't very many and the more common ones there are, essentially all from IBM, are highly polished.

Compared with C/C++, the polished PL/I compilers are terrific because, with the language features, they actually do really compile the work instead of just call functions. In fact, the early versions of PL/I did string, etc. manipulations by having the compiler call run time functions; then the result was much like what C/C++ programmers are forced to do.

The compiling of functions for string and bit manipulation was done in part to have PL/I be faster than the then common practice of using functions for such things in Fortran. Net, for string manipulation, PL/I is faster than Fortran, C, and C++ because it actually compiles the work and avoids the overhead of function calls. Here C/C++ are behind and have no easy way to catch up.

For 2, who knows PL/I is not about the language itself. For it being my favorite, I know it!

That it's my 'favorite' doesn't mean that I suggest that others use it. I used the IBM PL/I on OS/2 a few times; I have the IBM PL/I for Windows but don't even have it installed. On Windows I use Visual Basic .NET, if only because it has such good access to .NET, ADO.NET, and ASP.NET. In many ways, I would prefer PL/I, but it is not a practical option.

PL/I has some features that were deliberately included to make learning it relatively easy. E.g., PL/I has no reserved words! That is, all the 'key' words in the language can be used by programmers for their own identifier names. So, a beginner doesn't have to worry about using a reserved word. I taught some elementary parts of PL/I to some not very good students in the business school at Georgetown University, and they learned fine.

For 3, the only serious problem with 'type safety' is for pointers. True, in PL/I, pointers do not have 'types' based on what they point to. That is, any pointer can point to anything. But, then, using pointers in PL/I is not nearly as necessary or common as in C/C++, is quite advanced, and is not common. I liked using pointers because can really work with the memory and, at times, write some 'polymorphic' functions. Tricky work with pointers is always tricky, and that the pointers in PL/I are not 'strongly typed' didn't make the work harder. Again, PL/I is not nearly as dependent on pointers as C; a C programmer is forced to used pointers frequently, and PL/I programmer can do fine using pointers only rarely.

Otherwise on types, PL/I took the attitude that converting a string to floating point, etc., should need just an assignment statement. For execution time, there is a warning from the compiler when such a conversion might be expensive.

But PL/I is far better than 'cast': Cast is just an override of the 'strong typing', that is, immunity from the strong typing police. The problem with cast is that it's super tough to find HOW THE HECK the conversion is done. Mostly I don't much care about pleasing the strong typing police, but I do usually very much care about the details of how the conversion is done. Right from the start, the IBM PL/I documentation was fully explicit on the conversions of all the pairs of the 'elementary' (no aggravates) data types -- good.

For garbage collection, where is that in C/C++? There is garbage collection in Visual Basic .NET, but it was not easy to implement. There is always some question if garbage collection should be implemented by the run-time. The way I'm depending on garbage collection in Visual Basic is quite similar to how I depended on automatic storage in PL/I, and PL/I automatic storage is MUCH more efficient to implement than garbage collection. Here the excellent, and advanced, scope of names in PL/I are a big help.

PL/I does do quite well on memory management, especially with its attribute 'automatic' which, for each 'task', has in effect a 'stack of dynamic descendancy' and allocates and frees automatic storage just as would want across the quite advanced scope of name rules.

This automatic storage works great with the PL/I 'structures' where a 'structure' is a list of elementary data types, arrays, or arrays of structures, all efficiently mapped to sequential storage in a clever, easy to understand way. The 'extents' (string maximum lengths and array bounds) need only be known when the structure is to be allocated. So, in particular can pass arguments to routine parameters what are the extents. Or can do a calculation, enter a Begin-End block and do the automatic allocation inside that block. Works great. That can't do such things in C, especially for arrays, not even array parameters, is one of the most serious failings of C and, thus, C++. To get around the problem, end up using C structures or C++ classes, both of which are much less efficient. PL/I structures are about as efficient as Fortran arrays, depending on what is being done, a little more or a little less.

Then scope of names and dynamic descendancy are well coordinated with exceptional condition handling so that the code that executes in response to an exceptional condition can be 'on the stack' several levels back and, then, if it wishes, do a 'no-local goto' to pop the stack back to its own level. In this way, all the relevant automatic storage gets freed and lots of memory leaks get avoided.

The problem here with C/C++ is that a C programmer, and, thus, also the pre-processor definition of C++, do not have enough access to memory management to do such good things.

Moreover, C and C++ have nothing in the language about 'tasks' or threads, and PL/I does, did from the beginning. In particular, the storage attribute 'controlled' (roughly like malloc and free) is 'task-relative', that is, goes away when the task does. Files are also task-relative and get closed when the task goes away. Nice.

4. For the 'build tools', never had a problem. I was in the group at Yorktown Heights that did the artificial intelligence language KnowledgeTool (KT) which was a pre-processor to PL/I, and we did a lot of building but had no problems with 'build tools'. I was the guy who used dynamic descendancy in a tricky way to make the 'rule subroutines' in KT simple and efficient and won an award for the work.

Of course, for a scripting language we had Mike Cowlishaw's Rexx, and for an editor we had XEDIT with its macro language, right, the same Rexx. Rexx is a great candidate for the most elegant scripting, macro language going. Rexx was the main reason we had no problems with build tools.

Actually, can claim that for some years Rexx, with a few extensions for some lower level OS access, basically 'ran' all of IBM: There were about 4000 mainframes around the world connected with simple bisync lines. In the end, it all looked much like the Internet today. So, the mainframes were acting as both the servers and the routers. The hard work of the routing, security, etc. was done with 'server virtual machines' programmed mostly in Rexx with a few routines for some lower level access. It worked surprisingly well. Rexx was no toy.

"5. Where's the support for interoperability with other languages? C++ can be used with other languages through well-known and well-maintained paths. PL/I has no support."

A lot of nonsense. On IBM, PL/I used standard OS calling sequences. Calling Fortran, Cobol, assembler, and C was routine. I wrote a collection of routines in PL/I to call C to call the TCP/IP routines. Occasionally I called assembler from PL/I.

Got'a tell you, calling Visual Basic .NET 'managed code' from C won't be a picnic! In some of my current project, at one point I call some C from Visual Basic .NET managed code and have the effort fairly simple. On Windows, calling one language from another is okay as long as they are both 'managed code'. Otherwise, on Windows or nearly anything else, calling one language from another is at least a little tricky and, in general, tough.