Logo was developed by Seymour Papert at MIT. As a programming language its roots owe more to the development of artificial intelligence. I am a committed logophile influenced, of course, by Papert's book, Mindstorms.
If you have never come across the book, get a copy and read it. If only because of Papert's view of mathematics as a language. Since French children of even the lowest levels of academic ability have no problem learning to communicate in French, because they are brought up in a French-speaking environment (so, Papert reasoned), the reason why students were less able to communicate in mathematical and problem solving language was because they were not immersed in an environment that allowed them to develop such tools.
Logo was one approach to providing such an environment. Logo's simplicity lent itself to elementary education. Although its main application was in mathematics, to the point where some people think that Logo is nothing more than turtle geometry. Logo is much more than that.
In Mindstorms, Papert gives an example of using Logo to generate random poetry by combining lists of nouns, adjectives and verbs. The result was a group of students whose concept of grammar was enriched by participating in the exercise. Advocates of
To other creative teachers, Logo gave them the opportunity to create "Microworlds" for students to investigate. In the past, this appealed more to the mathematicians. However, there has been some interesting work done on constructing adventure and simulation games within Logo.
Whether you could use investigation of this sort of environment or construction of similar projects of your own as a key to developing language skills further will probably depend on the aptitudes and interests of the students you work with. That is one of the things I particularly enjoy about adult education. It allows you the flexibility to choose whichever set of tools you need to enable your students to achieve their goals
To the real enthusiast however, Logo is more than a programming language. It becomes an approach to learning. more heavily influenced by the cognitive school of thought developed by Piaget. The definitive place to look on the internet is the home of the Logo Foundation. Here you will find details of published papers on Logo, links to other Logo sites and details of user groups, workshops, newsgroups and listservs you can join.
There are also free versions of the Logo programming language available for download over the internet. As with so much of what I have mentioned here, you will find the details on the Logo Foundation's homepage.
There is one main obstacle to using Logo as a tool to assist in delivering ESL. In effect, you are learning/teaching problem solving skills within the framework of another , probably unfamiliar language. Of course, mathematicians do this all the time. However, for them, the benefits of this approach may be more immediate. For an ESL specialist who is also trying to simultaneously develop information literacy skills in his/her students, this is one approach. But, if this is not seen as a priority, then its application may be limited.