Libraries written in C do not have a huge run-time dependency.
In its minimum configuration, SQLite requires only the following routines from the standard C library:
memcmp() memcpy() memmove() memset() strcmp() strlen() strncmp()
In a more complete build, SQLite also uses library routines like malloc() and free() and operating system interfaces for opening, reading, writing, and closing files. But even then, the number of dependencies is very small. Other "modern" languages, in contrast, often require multi-megabyte runtimes loaded with thousands and thousands of interfaces."
Very laudable!
(I should also point out that SQLite could conceivably be compiled with small (in terms of lines of code) C compilers like Fabrice Bellard's Tiny C Compiler (TCC). Also SQLite's few required standard C library routines listed above could conceivably be coded inside of SQLite itself(!) (they are, after all, just additional lines of C code in a different place -- and those could conceivably be moved or copied) -- thus removing the dependency/requirement for any standard C library whatsoever!)
Anyway, we love SQLite!