If you are learning or developing for PIC10/12/16 today, . Use MPLAB XC8 – it is the direct, safe, and fully-supported evolution of Hi-Tech C.
The safest place to look is the "Compiler Archive" on Microchip’s official website. They often keep legacy installers available for registered users. hitech+c+compiler+for+pic10+12+16+mcus+v983+download+updated